When solving an equation, how do you check your answer?

Which pair of equations could not be used to solve the following equations for x and y?

Mary has 32 she bought 3 comic books that cost 4 each then she and her friend mowed a neighbor yard and earned 18

If postage costs $.54 for the first ounce and $.22 for the each additional ounce, calculate the cost of mailing a 10 - ounce envelope. A. $2.20 B. $5.08 C. $2.52 D. $5.40

If (-3, y) lies on the graph of y = (1/2) x, then y =

Ky wants to buy 3 shirts which were originally priced $49.96 each the store will discount the price of the third shirt and then apply a 7.1% tax to a total cost of all three shirts including the tax what will be the mean of the cost show your work

A pool service charges $40 per year for chemicals plus $70 per month for pool care. A second pool service's charges are shown in the table below. Number of Months (x) : 2, 3, 6, 8. Total Charge (y) : $190, $255, $450, $580.

What is the area of a rectangle with the length of 91 inches and a width of 45 inches?

What can 76 be divided by

At Kelli's skateboard shop, customers pay an upfront fee of $12 and then pay $3 per hour for each hour they use the skateboard. Write a rental equation for the cost of renting a skateboard at Kelli's shop. ht

Find the area of a square with length 6 1/3 inches. usethe appropriate unit of measurment