Question 840885
Let pounds of apple be x and peaches be y,
cost of 1 pound of apple = 2 and cost of peach is 1
then the cost of X pounds of apple = 2x and cost of Y pounds of peach = y

total pounds is 20 => x + Y = 20 --- 1
and total cost is 28 => 2x + y = 28  --2

Solving equ 1 and 2

x + Y =20
2x + y = 28
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x = 8

then Y = 12

Therefore 8 pounds of apple and 12 pounds of peach is needed to buy to spend exactly $28.