we have
4x-7y=28
Solve for y
that means -----> isolate the variable y
subtract 4x both sides
-7y=-4x+28
Divide by -7 both sides
y=(-4/7)x-28/7
y=(-4/7)x-4
Part 2
The perimeter of rectangle is equal to
P=2(L+W)
step 1
Find the perimeter of rectangle CARD
substitute the given values
P=2(2x-5+6x+10)
P=2(8x+5)
P=16x+10
step 2
Find the perimeter of rectangle BEST
P=2(10x+3+4x-7)
P=2(14x-4)
P=28x-8
step 3
find the difference
Difference=(16x+10)-(28x-8)
Difference=-12x+18