Answer:
x=11
Step-by-step explanation:
7x-9-4(x-1)=28
7x-9-4x+4=28
3x-5=28
3x=33
x=11
grand coulee dam (g) contains 2.5 times as much concrete as the hover dam (h)
Therefore,
g = 2.5 * h
h = 3.5 million
g = 2.5 * 3.5
g = 8.75 million yards of concrete
(2,2)
(x1+x2)/2, (y1-y2)/2
(-2+6)/2=(2)
(-2+6)/2=2
