Explore BrainMass

Explore BrainMass

    Graphing, Inequalities, slopes, Variables, and Elimination

    Not what you're looking for? Search our solutions OR ask your own Custom question.

    This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

    Please see attached. help with homework. equation, graphs.

    © BrainMass Inc. brainmass.com December 24, 2021, 9:09 pm ad1c9bdddf
    https://brainmass.com/math/graphs-and-functions/graphing-inequalities-slopes-variables-elimination-348485

    Attachments

    SOLUTION This solution is FREE courtesy of BrainMass!

    #1. Multiply 6/7 * -1/5
    -6/35

    #2. Simplify -5[-25-(29-31)]
    -5[-25-(-2)]
    -5(-23)
    115

    #3 solve 0.3x<-24
    x<-80
    #4 solve y-7>-18
    y>-11
    #5 find the slope of (-4,0) (0,1)
    m=dy/dx
    m=(0-1)/(-4-0)
    m=1/4
    #6 graph x + 5y=10
    Change to y=mx+b
    5y=-x+10
    y=(-1/5)x+2

    #7 trains A and B are traveling in the same direction on parallel tracks. Train A is traveling 60 mph and train B is traveling 64mph. Train A passes a station at 3:20pm. If train B passes the same station at 3:50pm at what time will train A catch up to train B?
    We need to figure out how much time it will take for those 4mph faster to catch up to a 30 minute head start. I assume we want to know how long it will take for B to catch A, not the other way around.

    Train A gets a 30 minute headstart, allowing it to move 30 miles ahead. Train B, in order to fill this gap, is basically moving at 4 mph compared to Train A. So we take 30 miles and divide by 4 mph, getting 7.5 hours. So 7.5 hours after Train B passes the station, it catches train A. 3:50 + 7:30 = 11:20PM

    #8 translate to an algebraic expression The product of 45% and some number
    0.45*x

    #9 is the coordinates a function (-3,7) (2,2) (3,1) (7,5)
    Yes
    We know this because none of the x values are repeated, and none of the y values are repeated
    #10 solve by substitution 8x+9y=-47 x=-5-2y
    8(-5-2y)+9y=-47
    -40-16y+9y=-47
    -40-7y=-47
    -7y=-7
    y=1
    x=-5-2
    x=-7
    (-7,1)
    #11 find the domain of the function g(x)=1/9-2x
    All real numbers (there is no value of x that makes this function untrue)

    #12find the indicated outputs for f(x)=5xsquare-4x
    I'll assume you want f(0), f(1), and f(2), but there was none given
    f(0)=0
    f(1)=5*1^2 - 4(1)
    f(1)=1
    f(2)=5*(2^2)-4(2)
    =5*4-8
    f(2)=32

    #13 solve the system of equations ( an ordered pair ) x+8y=8 x=7-8y
    No solution (there is no y value that is true for this, indicating parallel lines)
    #14solve the compound inequality 7>-4x+6 or 8<_-3x=4
    7>-4x+6
    1>-4x
    -1/4<x
    THEN
    5<_-3x
    -5/3_>x
    Therefore
    -1/4<x<_-5/3

    #15graph using the slope and the y intercept y= 8/7x +7
    y-intercept is 7. Slope is 8/7

    #16 use distributive property 4(w-4)=8
    4w-16=8
    4w=24
    w=6
    #17 solve -4&#8804;3x-x&#8804;-2
    -4&#8804;2x&#8804;-2
    -2&#8804;x&#8804;-1
    #18 graph and identify y intercept y+x=-9

    y-intercept=-9

    #19 is (-8,3) a solution to 8x-4y=-4
    8*(-8)-4(3) = -4
    -64-12 = -4
    No it is not
    #20 use the intercepts to graph the equation x + 5y =10
    x-int=10
    y-int=2

    #21 multiplication principle -3/4x+-9/10
    I am not sure what is being asked here, since it does not equal anything

    #22 are the lines parallel, perpendicular, or neither 2x+3y=4 3x+2y=2
    Change to y=mx+b
    y=-2/3x +4/3
    y=-3/2x + 1

    They are neither, since parallel requires the same slope and perpendicular requires the negative reciprocal. Neither is present.
    #23 soybean meal is 12%protein, cornmean is 6% protein. How many of each should be mixed together to get a 240lb mixture that is 9% protein? How many pounds of cornmeal? How many pounds of soybean
    9% is the midpoint between 12 and 6, so we can mix them 50:50. 120lb of cornmeal, and 120lb of soybeans

    #24 find the slope and the y intercept f(x)=-3x-5
    slope= -3
    y-int= -5

    #25 find the domain and the function p(x)=xsquare-2x+3
    Domain: All real numbers
    Range: All real numbers
    #26 find the slope (8,5) and (9,-2)
    m=dy/dx
    m=(5-(-2))/(8-9)
    m=7/-1
    m=-7
    #27collect like terms 13x+6y-7x-9y
    13x-7x+6y-9y
    6x-3y
    #28 the width of a rectangle is fixed at 16cm. What lengths will make the perimeter greatger rgan 90cm?
    We can set up a function
    P=2w+2L
    w=16
    We want P>90
    Therefore, 2w+2L>90
    2(16)+2L>90
    32+2L>90
    2L>58
    L>29
    So if L is greater than 29, then we are successful
    #29 solve using multiplication principle -2x>1/9
    (9)*-2x>9*(1/9)
    -18x>1
    x<-1/18

    #30 Amy paid 69.51 for a pair of running shoes during a 30% off sale. What was the regular price?
    70% of the price is 69.51
    0.70x=69.51
    x=99.3
    $99.30
    #31 solve 5/4x+1/8x=5/8+x
    8(5/4x+1/8x)=8(5/8x+x)
    10x+x=10x+8x
    11x=18x
    -7x=0
    x=0
    #32 Media services charges $40 for a phone and 20/month for its economy plan. The equation c=20t+40 describes the total cost, c, of operating a media service phone for t months. The total cost of 10 months of service is? If a customer had $90 available how many months of service can he receive?
    10 months, t=10
    c=20(10)+40
    200+40
    240$

    c=90
    90=20t+40
    50=20t
    t=2.5 months

    #33 elimination method 3r-5s=-16 5r+3s=30
    3(3r-5s=-16)
    5(5r+3s=30)
    9r-15s=-48
    25r+15s=150
    34r=102
    r=3
    3(3)-5s=-16
    -5s=-25
    s=5
    #34 solve 5+5x<35
    5x<30
    x<6
    #35 evaluate z+y/6 for z=46 and y =2
    46+2/6
    46 1/3
    #36 solve 8x-(3x+7)=28
    5x-7=28
    5x=35
    x=7
    #37 50% of what number is 15?
    0.5x=15
    x=30
    #38 graph the line containing the given pair of points and find the slope (2,0), (-4,-3)

    slope = 1/2
    #39 solve the system, graph, and classify as consistent, inconsistent, dependent or independent 8x-4y=-16 4y-8x=16
    y=2x+4
    and
    y=2x+4
    These are consistent and dependent

    #40 graph the inequality on a plane 4x+5y&#8804;20

    #41 on 3 consecutive passes a football team gains 7 yards, loses18yards, and gains 46 yards. What number represents the total net yardage??
    7-18+46= 35 gained
    #42 h(x)=2.75x+71.48 predcit height of 33cm
    2.75(33)+71.48
    162.23
    #43 find slopx=-7
    There is no slope since this line is vertical. It is undefined
    #44 multiplcation principle 9x=-72
    1/9(9x)=1/9(-72)
    x=-8
    #45 graph y&#8805;-3 x&#8805;4

    #46 solve for indicated letter d=8h, for h
    h=d/8
    #47 solve then graph 6x&#8805;30
    x&#8805;5

    #48 eliminatiion method 4x+5y=5 8x+10y=10
    (-2)4x+5y=5
    8x+10y=10
    -8x-10y=-10
    0=0
    These are the same equation

    #49 solve .08x+2&#8804;1.2x-9
    2&#8804;0.4x-9
    11&#8804;0.4x
    27.5&#8804;x
    #50

    This content was COPIED from BrainMass.com - View the original, and get the already-completed solution here!

    © BrainMass Inc. brainmass.com December 24, 2021, 9:09 pm ad1c9bdddf>
    https://brainmass.com/math/graphs-and-functions/graphing-inequalities-slopes-variables-elimination-348485

    Attachments

    ADVERTISEMENT