C^2+7 would equal 88. the first equation states that C=9, so you can just plug in 9 for C
Divide them and then multiply
B.16 because 800 divided by 50 is 16
The distributive property: a(b + c) = ab + ac
(-7c + 8d)0.6 = (-7c)(0.6) + (8d)(0.6) = -4.2c + 4.8d
