Question

Evaluate b(-7), when b(c) = 2c³5c² - 6c - 13.

Answer 1

168015

Explanation:

b(c) = 2c³5c² - 6c - 13

b(7)=2(7)³5(7)²-6(7)-13

b(7)=2(343)5(7)²-6(7)-13

b(7)=(686) 5(49)-6(7)-13

b(7)=(686) (245)-6(7)-13

b(7)=(686) (245) -42-13

b(7)=168070-42-13

b(7)=168028-13

b(7)=168015

(Usually this is how you would solve it but because there was no sign between the 2c^35c^2 I got sort of confused so I just multiplied, if wrong I'm sorry..)

Answer 2

`b(-7)=-168041`.

Explanation:

1. Write the function.

`b(c)=2c^(3) 5c^(2) -6c-13`

2. Substitute "c" by "-7" in the function.

`b(-7)=2(-7)^(3) 5(-7)^(2) -6(-7)-13`

3. Calculate.

`b(-7)=2(-343) 5(49) -(-42)-13\\ \\b(-7)=-168070 +42-13\\ \\b(-7)=-168041`