Question

expressions and equations
when x is 4, by how much does the value of 5x³ exceed the value of 2x⁵?
select one answer
a. 2.5
b. 36
c. 1920

Explanation:

Step1: Define the difference expression

We need to find how much $3x^3$ exceeds $2x^3$, so first set up the difference:
$3x^3 - 2x^3$

Step2: Simplify the expression

Combine like terms:
$3x^3 - 2x^3 = x^3$

Step3: Substitute $x=4$

Replace $x$ with 4 in the simplified expression:
$4^3 = 4\times4\times4 = 64$
Wait, correction: Re-express the original difference correctly first, then substitute:

Step1: Calculate $3x^3$ at $x=4$

Compute the value of the first term:
$3\times4^3 = 3\times64 = 192$

Step2: Calculate $2x^3$ at $x=4$

Compute the value of the second term:
$2\times4^3 = 2\times64 = 128$

Step3: Find the difference

Subtract the second value from the first:
$192 - 128 = 64$
*(Note: 64 is the correct result, assuming a typo in option B as 36 is incorrect; if the original question had $x=3$, 36 would fit, but with $x=4$, the correct difference is 64. However, if we follow the given options and assume the question intended $x=3$:

Step1: Calculate $3x^3$ at $x=3$

$3\times3^3 = 3\times27 = 81$

Step2: Calculate $2x^3$ at $x=3$

$2\times3^3 = 2\times27 = 54$

Step3: Find the difference

$81 - 54 = 27$, still not matching. Alternatively, if the question was $3x^2 - 2x^2$ at $x=6$, it would be 36. But based on the written question with $x=4$, the correct calculation is below)*

Answer:

64
(If forced to choose from the given options, there is a discrepancy, but mathematically, when $x=4$, $3x^3$ exceeds $2x^3$ by 64)