Equations
An invoice for 17 brooms and 22 mops totaled 211.84. Another invoice for 20 brooms and 14 mops totaled 191.00 How much did each broom cost, and how much did each mop cost (to the nearest cent)?
© BrainMass Inc. brainmass.com December 24, 2021, 4:55 pm ad1c9bdddfhttps://brainmass.com/math/algebra/determining-system-equations-solve-unknown-variables-15346
SOLUTION This solution is FREE courtesy of BrainMass!
Let the brooms cost be denoted by x and the mops cost be denoted by y
invoice for 17 brooms and 22 mops totaled 211.84
or 17 x + 22 y= 211.84 ---Equation1
invoice for 20 brooms and 14 mops totaled 191.00
or 20 x + 14 y= 191 ---Equation2
Now we have two equations and and an equal number= two unknowns
Thus the equations can be solved simultaneously to give the values of x and y
17 x + 22 y= 211.84 ---Equation1
20 x + 14 y= 191.00 ---Equation2
Multiplying both the left and right hand sides of an equation does not change the equation
We multiply equation 1 throughout by 20
17 x + 22 y= 211.84 ---Equation1 x 20
= 340 x + 440 y= 4236.80
We multiply equation 2 throughout by 17
20 x + 14 y= 191.00 ---Equation2 x 17
= 340 x + 238 y= 3247.00
Thus we get equations 1 and 2 as
340 x + 440 y= 4236.8 ---Equation1
340 x + 238 y= 3247.00 ---Equation2
Next we subtract equation 2 from equation 1
340 x + 440 y= 4236.8
340 x + 238 y= 3247
0 x + 202 y= 989.80
0r 202 y= 989.80
or y= 4.90 =989.8/202
We can substitute the value of y= 4.90 in either of equation 1 or 2 to get the value of x
Thus equation 1=
17 x + 22 y= 211.84 ---Equation1
Substituting the value of y= 4.90 in this equation
17 x + 107.8 = 211.84
or 17 x= 104.04 =211.84-107.8
or x= 6.12 =104.04/17
Thus the value of x= price of the broom= $6.12
The value of y= price of the mop= $4.90
https://brainmass.com/math/algebra/determining-system-equations-solve-unknown-variables-15346