Pretest: Polynomial Expressions

Type the correct answer in the box. Use numerals instead of words. If necessary, use / for the fraction bar.

Subtracting [tex]\( 3x^2 + 4x - 5 \)[/tex] from [tex]\( 7x^2 + x + 9 \)[/tex] results in a polynomial. After subtracting [tex]\( 4x^2 - 3x \)[/tex] from this polynomial, the difference is [tex]\( \square \)[/tex].



Answer :

Let's solve the problem step by step by performing the given polynomial subtractions.

Given polynomials:
1. [tex]\(7x^2 + x + 9\)[/tex]
2. [tex]\(3x^2 + 4x - 5\)[/tex]
3. [tex]\(4x^2 - 3x\)[/tex]

Step 1: Subtract the second polynomial from the first polynomial.

We need to subtract [tex]\(3x^2 + 4x - 5\)[/tex] from [tex]\(7x^2 + x + 9\)[/tex]:

[tex]\[ (7x^2 + x + 9) - (3x^2 + 4x - 5) \][/tex]

Distribute the negative sign and combine like terms:

[tex]\[ 7x^2 + x + 9 - 3x^2 - 4x + 5 \][/tex]

Combine like terms:

[tex]\[ (7x^2 - 3x^2) + (x - 4x) + (9 + 5) \][/tex]

[tex]\[ 4x^2 - 3x + 14 \][/tex]

So, the result of the first subtraction is:

[tex]\[ 4x^2 - 3x + 14 \][/tex]

Step 2: Subtract the third polynomial from the result of the first subtraction.

Next, we need to subtract [tex]\(4x^2 - 3x\)[/tex] from [tex]\(4x^2 - 3x + 14\)[/tex]:

[tex]\[ (4x^2 - 3x + 14) - (4x^2 - 3x) \][/tex]

Distribute the negative sign and combine like terms:

[tex]\[ 4x^2 - 3x + 14 - 4x^2 + 3x \][/tex]

Combine like terms:

[tex]\[ (4x^2 - 4x^2) + (-3x + 3x) + 14 \][/tex]

[tex]\[ 0 + 0 + 14 \][/tex]

[tex]\[ 14 \][/tex]

So, after performing both subtractions, the final result is:

[tex]\[ \boxed{14} \][/tex]