Question

Subtract and simplify: (3x^2 + 7) – (x^2 – 6x + 4)
I answered it, can someone check my answer?
2x^2+6x+3

Answer 1

(3x^2 - x^2) + 6x + (7 - 4)
(3 - 1)x^2 + 6x + 3
2x^2 + 6x + 3

Correct

Answer 2

Looks like you're getting the hang of this :o)

Answer 3

Hero?

Answer 4

Wanna check another one of my answers?

Answer 5

I can check your answers.

Answer 6

k, here is another one

Answer 7

Find the volume of the box: (x+3) (5x-4) (2x-1)
I answered 10x^3+17x^2-35x+12

Answer 8

(x + 3)(5x - 4)(2x - 1)
= (x(5x - 4) + 3(5x - 4))(2x - 1)
= (5x^2 - 4x + 15x - 12)(2x - 1)
= (5x^2 + 15x - 4x - 12)(2x - 1)
= (5x^2 + 11x - 12)(2x - 1)
= 5x^2(2x - 1) + 11x(2x - 1) - 12(2x - 1)
= 10x^3 - 5x^2 + 22x^2 - 11x - 24x + 12
= 10x^3 + (22 - 5)x^2 -(11 + 24)x + 12
= 10x^3 + 17x^2 - 35x + 12

Correct

Answer 9

Great!

Answer 10

You up for a few more?

Answer 11

I guess

Answer 12

Use FOIL to multiply the two binomials.

(b + 3)(b – 9)

Answer 13

i answered b^2-6b-27

Answer 14

(b + 3)(b - 9)
= b(b - 9) + 3(b - 9)
= b^2 - 9b + 3b - 27
= b^2 -(9 - 3)b - 27
= b^2 - 6b - 27

Correct

Answer 15

kk only like 2 more?

Answer 16

In case you're wondering what that second step is, it's an application of the distributive rule. Highly recommend using it rather than FOIL

Answer 17

10x(9x^2+60x+7)
I answered 90x^3+60x^2+70x

Answer 18

And ya i tried FOIL and I really didn't like it

Answer 19

Actually if the original question is 10x(9x^2 + 60x + 7) then

90x^3 + 600x^2 + 70x is the correct result.

Answer 20

Expand the squared binomial.

(x – 4)^2
I didn't really understand this one but I guessed that it would be x^2-16?

Answer 21

oops and the original was 6 not 60

Answer 22

(x - 4)^2
= (x - 4)(x - 4)
= x(x - 4) - 4(x - 4)
= x^2 - 4x - 4x + 16
= x^2 -(4 + 4)x + 16
= x^2 - 8x + 16

Answer 23

O ok

Answer 24

The expression (2x + 3)(3x + 4) simplifies to which of the following?

Answer 25

i don't understand that one ^^^

Answer 26

Use distributive rule or FOIL:

(2x + 3)(3x + 4)
= 2x(3x + 4) + 3(3x + 4)
= 6x^2 + 8x + 9x + 12
= 6x^2 +(8 + 9)x + 12
= 6x^2 + 17x + 12

Answer 27

Simplify means the same as expand or FOIL in this case.

Answer 28

Ok good because thats the one i chose!

Answer 29

K thats all the questions thanks so much!!!!!

Answer 30

Yup. I prefer distributive rule over FOIL because FOIL actually skips an intermediate step, which so happens to be the distributive rule.

Answer 31

Furthermore, FOIL is just an acronym. Distributive rule is an actual mathematical property.

Answer 32

Great job on all the questions.

Answer 33

@skullpatrol, is there something I can help you with?

Answer 34

@Hero No, I was just admiring your great work :-)

Answer 35

@Hero just got all those questions graded I got 100%....Thnx!

Answer 36

Awesome :D