Keigh2015 one year ago Choose the correct simplification of the expression (7x − 3)(4x2 − 3x − 6). 28x3 − 33x2 − 33x − 18 28x3 + 33x2 − 33x + 18 28x3 − 51x2 − 33x + 18 28x3 − 33x2 − 33x + 18

1. Keigh2015

@iGreen @brina15

2. anonymous

I'm helping you now give me two seconds.

3. iGreen

Just multiply the two expressions together.

4. iGreen

$$\sf (7x - 3) \times (4x^2 − 3x − 6)$$

5. Keigh2015

28?

6. anonymous

First work with the first term, 7x * 4x^2 and you get 28x^3. Then multiply the first term of the binomial and second term of the trinomial. so 7x * -3x what do you get? @Keigh2015

7. iGreen

No, it's kind of like the last question.

8. iGreen

Multiply all the terms in the first parenthesis to all the terms in the second parenthesis.

9. anonymous

@iGreen let me help her I'm showing her an easy way.

10. iGreen

$$\sf 7x \times 4x^2$$ $$\sf 7x \times -3x$$ $$\sf 7x \times -6$$ $$\sf -3 \times 4x^2$$ $$\sf -3 \times -3x$$ $$\sf -3 \times -6$$

11. iGreen

Alright @alexistheking777

12. anonymous

@Keigh2015 You see what iGreen posted? Give me the answers to the problems he posted. It is part of the equation and will help you.

13. Keigh2015

ok hold on

14. iGreen

Yeah, after you find those just combine any like terms and you're done..

15. anonymous

16. Keigh2015

almost

17. Keigh2015

In this order 28x^2 -21x -42x -12x^2 9x 18

18. anonymous

Your right for all the ones except the first two. The numbers are right but you forgot to combine the exponents so think of x^2 * x as x^2+1 since x has the exponential value of 1. So you would get an exponential value of 3. So it would be 28x^3. And same goes for x * x so it would be x^1+1 which is 2. So it should be -21x^2. 28x^3 -21x^2 -42x -12x^2 9x 18 Now combine like terms (that is terms with same exponent. So what is -21x^2 + (-12x^2)

19. anonymous

@Keigh2015

20. Keigh2015

28x^3-33x^2

21. anonymous

Yes because 28x^3 is the only term with an exponential value of 3 and -21 + (-12) is like -21 - 12 which is 33. Then you replace the x and exponential value so its -33x^2. Good job, now we can eliminate answe C since the second term is 51x^2 which is wrong. So now what is -42x + 9x?

22. Keigh2015

-33x

23. anonymous

By the way we can also eliminate B as well since the second term is positive and ours is negative. And yes it is -33x. Last step is to add the 18 to your equation so combine all those answers you just gave me.

24. Keigh2015

28x^3-33x^2-33x+18

25. anonymous

Correct so when you look at the answers the only one that matches it is D. I hope this helped you don't forget to close this question and choose the person that was the greatest help to you by hitting best response and have a wonderful day. @Keigh2015

26. Keigh2015

thank you for the help and you too @alexistheking777

27. anonymous

No problem.

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