The answer would be the third one
5x+2y = 20
For every hardcover book (x) you will be charged 5$.
For every paperback book (y) you will be charged 2$.
The amount of both types of books you buy has to be under or equal to 20$
This is Commutative property of addition
What you need to do is do the formula of Area=1/2×Height (Base B +Base A) Base B is bottom Base A is the top then you divide by 2 In this case 1/2 ×8/1 ×(12+15)=108
The system of equations:2 y = - x - 12 y = x + 5---------------------- x - 1 = x + 5- 2 x = 5 + 1- 2 x = 6x = - 6 : 2x = - 32 y = - 3 + 52 y = 2y = 1The solution is ( - 3 , 1 ).Answer: The x-coordinate of the solution to the system is: x = - 3.
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