Question

adding and subtracting polynomials!
39.(-3x^2+4x+7)+(7x^2-3x-12)
40.(2x^2-5x-9)-(43x^2-7x+12)
41.(x^2-4x-11)+(8x^2+11x+15)
42.(4x^2-9x-12)-(2x^2+9x-11)

Answer 1

Please help me!

Answer 2

39. \((-3x^{2}+7x^{2}) + (4x-3x) +(7-12) = ?\)

Answer 3

@satellite73

Answer 4

39. -3x^2+4x+7+7x^2-2x-12
= -3x^2+7x^2+4x-2x+7-12
= 4x^2+2x-5
If you understand what I did there, all you need to do is follow the same kind of principles then you should get the rest. With 40. and 42. all you need to do is picture that a -1 is in front of the second bracket and multiply that -1 by everything inside the bracket then follow the same pattern as I have shown previously.

Answer 5

Just make sure to collect like terms, which means you have to add/subtract all the terms that have a x^2, x, and a base number together.

Answer 6

39. 4x^2+x-5
40. -41x^2-12x+3
41. 9x^2+7x+4
42. 2x^2-23

Answer 7

thanks guys

Answer 8

but can you explain how you got 40.

Answer 9

combine light terms

Answer 10

2x^2+-43x^2=-41x^2 -5x+-7x=-12x -9+12=3

Answer 11

(2x^2-5x-9)-(43x^2-7x+12)
= 2x^2-5x-9-43x^2+7x-12
= 2x^2-43x^2-5x+7x-9-12
= 41x^2+2x-21
You have to make sure to get all the like terms together. Also make sure to distribute the negative into the brackets which will affect everything else inside the brackets.

Answer 12

Sorry, -41x^2+2x-21.

Answer 13

and 42.

Answer 14

well i kind of get it now thank you!

Answer 15

shonari ur wrong im right

Answer 16

You forgot to distribute the negative into the brackets, therefore giving you a positive 7 rather than a negative 7.

Answer 17

i guess i will show it to my teacher tommorow to see which one is right!

Answer 18

Hopefully all goes well, good luck.

Answer 19

when u combine -5-7 into the calculator it will give u -12 not 2

Answer 20

i could check it online!

Answer 21

-(43x^2-7x+12) means that you will multiply -1 and 43, -1 and -7 and -1 and 12.

Answer 22

2x2−5x−9−(43x2−7x+12)
=2x2+(−5x)+(−9)+(−43x2)+7x+(−12)
=(−41x2)+2x+(−21)
=−41x2+2x−21
source @ http://www.mathpapa.com/algebra-calculator.html

Answer 23

sorry ur right i didn't c the (-)

Answer 24

so @shonari_d was right!

Answer 25

It's alright survivor, we all make mistakes!

Answer 26

if i could i would give survivor a medal too!

Answer 27

thank you guys so much! i understand more than i did a ouple of dys ago! bye!

Answer 28

Anytime, cya later!

Answer 29

http://www.acalculator.com/math-calculators.html