Kate multiplied two binomials using the distributive property. She made a mistake in one of the steps. Where did she first make a mistake?

[tex]\[
(x-2)(3x+4)
\][/tex]

1. [tex]\((x-2)(3x) + (x-2)(4)\)[/tex]
2. [tex]\((x)(3x) + (-2)(3x) + (x)(4) + (-2)(4)\)[/tex]
3. [tex]\(3x^2 + 6x + 4x - 8\)[/tex]
4. [tex]\(3x^2 + 10x + 8\)[/tex]

A. Step 3
B. Step 2
C. Step 4
D. Step 1



Answer :

Let's go through Kate's steps to identify where she made a mistake.

### Step 1
Kate needs to apply the distributive property to the binomials [tex]\((x - 2)(3x + 4)\)[/tex]. She does this correctly in the first step:
[tex]\[ (x-2)(3x) + (x-2)(4) \][/tex]
This step is correct.

### Step 2
Next, she needs to distribute each term in the first binomial to each term in the second binomial:
[tex]\[ (x)(3x) + (-2)(3x) + (x)(4) + (-2)(4) \][/tex]
Breaking it down:
[tex]\[ 3x^2 + (-6x) + 4x + (-8) \][/tex]
This step is also correct.

### Step 3
Kate combines the like terms:
[tex]\[ 3x^2 + (-6x) + 4x - 8 \][/tex]
Simplifying further, she should have combined the [tex]\( -6x \)[/tex] and [tex]\( 4x \)[/tex]:
[tex]\[ 3x^2 - 2x - 8 \][/tex]
So she should have had:
3x^2 + 4x - 6x - 8 = 3x^2 - 2x - 8
This step is correct as well.

### Step 4
However, examining her final result:
[tex]\[ 3x^2 + 10x - 8 \][/tex]
Shows that she incorrectly combined the terms 4x and -6x that result should be -2x, but she wrote +10x instead. Therefore, the first error appears in:
[tex]\[ \boxed{\text{Step 4}} \][/tex]

The correct answer is C. Step 4.

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