Please help me in this question
question is given below:

Satchi found a used bookstore that sells pre-owned dvds and cds. dvds cost $9 each, and cds cost $7 each. satchi can spend no more than $45.

The value of x in this system of equations is 1. 3x + y = 9 y = –4x + 10 substitute the value of y in the first equation: combine like terms: apply the subtraction property of equality: apply the division property of equality: 3x + (–4x + 10) = 9 –x + 10 = 9 –x = –1 x = 1 what is the value of y?

Your company will replace the asphalt roofs on all the buildings at the factory complex shown below. the buildings have flat roofs. you charge according to the total roof area. what is this area, in square yards?