Add up equation 1 and 2 to eliminate b
(a+b)+(-b+c)=3+3 => a+c=6
subtract this new equation from the third equation:
(a+2c)-(a+c)=10-3 =>c=4
plug in c=4 in a+c=6 =>a=2
a+b=3, a=2 =>b=1
1760/40 = 44
He covered 44 ft^2 per lb.
2640/60 = 44
Again, he covered 44 ft^2 per lb.
In both cases, he covered 44 square feet per pound.
To cover 4480 sq ft, he needs:
4480/44 = 101.818181... = 101 9/11 pounds
Answer:
33
Step-by-step explanation:
8(2)^2 + 2(2) -3 = 33