Question

Evaluate: 4x3 - 7x2 for x = 3

Answer 1

Answer:

45

Step-by-step explanation:

4$x^{3}$ - 7$x^{2}$ for x = 3

Substitute 3 in for x

4($3^{3}$) - 7($3^{2}$)

4(3·3·3) - 7(3·3)

4(27) - 7(9)

108 - 63

45

Answer 2

Answer:

45

Step-by-step explanation:

Hi there!

We are given 4x³-7x² and we need to evaluate the expression if x=3.

To do this, substitute 3 as x into the expression, and then use the order of operations to solve

so substitute 3 as x into the expression (remember: x² is x*x, or (x)²)  

4(3)³-7(3)²

now using the order of operations, start by evaluating the exponents

(3)³=3*3*3=9*3=27

(3)²=3*3=9

the expression then becomes:

4*27-7*9

multiply

108-63

subtract

45

Hope this helps! :)