Question

Evaluate 5x3 - 21 + 7 when x = -2.

Answer 1

The simplified answer to the given equation is -54.

Explanation:

For this problem, we are given the value of x.

x = -2

So, let's plug in this value into our expression soit can be easier to solve.

5(-2)³ - 21 + 7

First, simplify the exponents.

5(-8) - 21 + 7

Now, multiply 5 by -8.

-40 - 21 + 7

Subtract -40 from 21.

-61 + 7

Add 7 to -61.

-54

Answer 2

26

Explanation:

5x³ - 21 + 7

x = 2

then:

5x³ - 14

5*2³ -14

5*8 - 14

40 - 14

26