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Basic Algebra

Find Divisibility Rules for the Numbers from 2 to 13

Derive rules to test whether a number is divisible by N, where N ranges from 2 to 13. E.g. A number is divisible by 3 if the sum of the digits is divisible by 3. Show that a palindromic number which has an even number of digits is always divisible by 11.

Algebra word problems: miles per gallon

In a family there are two cars. In a given week, the first car gets an average of 25 miles per gallon, and the second car gets 40 miles per gallon. The two cars combined drive a total of 2100 miles in that week, for a total gas consumption of 60 gallons. How many gallons were consumed by each of the two cars that week?

Filling an aquarium tank

An aquarium tank can hold 7700 liters of water. There are two pipes that can be used to fill the tank. The first pipe alone can fill the tank in 77 minutes. The second pipe can fill the tank in 44 minutes by itself. When both pipes are working together, how long does it take them to fill the tank?

Simplifying Expressions

Simplify. Assume a and b are positive real numbers and m and n are rational numbers. ( a^-3/mb^6/n)^-1/3 ------------------ (a^-6/mb^9/n)

Find the LCD for the rational expressions

Find the LCD for the following rational expressions, and convert each rational expression into an equivalent rational expression with the LCD as the denominator. 4/x -y , 5x/ 2y - 2x

Minimum and maximum surface areas of a cube are found.

I need to find the maximum and minimum surface areas for 2 cubes with a total volume of 432 in^3. No other perameters are specified. I've been able to use common sense to find the max is 432 sq/inches (two 6"^3 cubes) and min is 343.051 sq (one 7.5595"^3 cube and one cube of 0.171"^3). I need help with the equations for the maxi

Solve the equation y = x2 - 6x + 8 = 0

Using the quadratic equation y = x2 - 6x + 8 = 0, perform the following tasks: a)Solve by factoring, b)solve by completing the square, c)solve by using the quadratic formula

Algebra and Trigonometry (16 Problems)

1. Write an equation for the circle that passes through the points: (1, -1), (-5, 7), and (-6, 0). 2. Express the polar equation in rectangular form. 3. Find the total area enclosed by the graph of the polar equation r = 1 + cos 2θ. 4. Write the equation of the line tangent to the parametric curve x = tcos t, y

Graphing and Solving Systems of Inequalities

1. Graph the inequality. y  1 2. Graph the inequality. y  3x 3. Given f(x) = 4x + 1, find f(3). 4. Given f(x) = 5x2 - 3x + 1, find f(-2). A) -13 B) 15 C) -25 D) 27 5. Given f(x) = x2 + 5x + 3, find f(0). 6. Rewrite the equation 4x - 10y = 11 as a function of x. A) B) C)

Logarithms

Please answer the following questions: 1. Find the domain of the function f(x) = ln(x - 7). 2. Simplify: log 1000 3. Write as a single logarithm (DO NOT find approximations): 2 log 4 + log x - log2. 4. Expand and simplify: ln(e^x). 5. Solve for x: log(x - 4) + log 2 = 1.