Question

If c=8 which expression has the greater value, 5c^(3)+982 or 2c^(4)−7c? Please help!!!!

Answer 1

Well, let's plug c=8 in both expressions and see which number is larger:

`5c^(3)+982\to 5\cdot 8^3+982 = 5\cdot 512+982=2560+982=3542`

`2c^(4)−7c\to 2\cdot 8^4-7\cdot 8 = 2\cdot 4096-56=8192-56=8136`

Answer 2

Explanation:

If c = 8, then:

5c^(3)+982 => 5(8)^3 + 982 = 3542

and

2c^(4)−7c = c(2c^3 - 7) => 8(2*512 - 7) = 8(1017) = 8136

So the second expression has the greater value when c = 8.