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11 votes
11 votes
Multiply: (3x+7)(5x^2-3x+6)

User Fancy
by
3.2k points

2 Answers

19 votes
19 votes

Answer:

15x^3+26x^2-3x+42

Explanation:

(3x+7)(5x^2-3x+6)

15x^3-9x^2+18x+35x^2-21x+42

15x^3-9x^2+35x^2+18x-21x+42

15x^3+26x^2-3x+42

User Vishal Khakhkhar
by
3.0k points
24 votes
24 votes

Answer:

15x³ + 26x² - 3x + 42

Explanation:

Hi there!

We are given the polynomials 3x+7 and 5x²-3x+6

We want to multiply them together

(3x+7)(5x²-3x+6)

To that, we need to distribute each term of the binomials to each other, and then add them together.

What this means is that we need to multiply 3x by 5x², -3x, and 6, then add them together. Then, multiply 7 by 5x², -3x, and 6. Add those together, and then add everything together.

So, let's first start by multiplying 3x by everything:

3x * 5x² = 15x³

3x * -3x = -9x²

3x * 6 = 18x

Add them together: 15x³ + -9x² + 18x

Now with 7:
7 * 5x² = 35x²

7 * -3x = -21x

7 * 6 = 42

Add them together: 35x² + -21x + 42

Now add 15x³ + -9x² + 18x and 35x² + -21x + 42 together:
15x³ + -9x² + 18x + 35x² + -21x + 42

Combine like terms:

15x³ + 26x² - 3x + 42

Hope this helps!

User David Undy
by
2.9k points