Exponents & Radicals Unit Test

9 of 199 of 19 Items

Question
Which of the following correctly identifies the first and last terms of the expression 4x3+3x−10+(2x−1)(−3x2+5)
?(1 point)
Responses

The first term is 4x3
. The last term is 5.
The first term is 4 x cubed . The last term is 5.

The first term is −2x3
. The last term is −15
.
The first term is negative 2 x cubed . The last term is negative 15 .

The first term is −2x3
. The last term is −10
.
The first term is negative 2 x cubed . The last term is negative 10 .

The first term is 4x3
. The last term is −5
.
The first term is 4 x cubed . The last term is negative 5 .
Skip to navigation

1 answer

To find the first and last terms of the expression \( 4x^3 + 3x - 10 + (2x - 1)(-3x^2 + 5) \), we first need to simplify it by distributing \( (2x - 1)(-3x^2 + 5) \).

  1. Distributing (2x - 1) with (-3x² + 5): \[ (2x)(-3x^2) + (2x)(5) + (-1)(-3x^2) + (-1)(5) \] \[ = -6x^3 + 10x + 3x^2 - 5 \]

  2. Now add this to the original expression: \[ 4x^3 + 3x - 10 + (-6x^3 + 10x + 3x^2 - 5) \] Combine like terms:

    • For \(x^3\): \( 4x^3 - 6x^3 = -2x^3 \)
    • For \(x^2\): \( 0 + 3x^2 = 3x^2 \)
    • For \(x\): \( 3x + 10x = 13x \)
    • Constant terms: \( -10 - 5 = -15 \)

Putting it all together gives: \[ -2x^3 + 3x^2 + 13x - 15 \]

From the simplified expression \( -2x^3 + 3x^2 + 13x - 15 \):

  • The first term is \( -2x^3 \).
  • The last term is \( -15 \).

The correct response is: The first term is −2x³. The last term is −15.