Question

Simplify expression

Answer 1

(3x^4 + 9x^3 – 7x + 15) + (–6x^4 – 8x^2 + 5x – 3)

Answer 2

@hartnn

Answer 3

add like terms

Answer 4

(3x^4+6x^4)+(5x-3)...?

Answer 5

\(\color{#0cbb34}{\text{Originally Posted by}}\) @shaleiah
(3x^4 + 9x^3 – 7x + 15) + (–6x^4 – 8x^2 + 5x – 3)
\(\color{#0cbb34}{\text{End of Quote}}\)

x^4 terms:

3x^4, -6x^4
>>> 3x^4-6x^4 = (3-6)x^4 = -3x^4
got this?

x^3 terms:
+9x^3

can you do the same for x^2 terms?

Answer 6

there is only one 'x^2' term, -8x^2
so keep it as it is.

what are 'x' terms?

Answer 7

(7x+5+5x-3)

Answer 8

(3x^4 + 9x^3 \(\Large \color{red}– 7x\) + 15) + (–6x^4 – 8x^2 \(\Large\color{red}+ 5x\) – 3)

-7x +5x = (-7+5)x

Answer 9

lastly, all the constants,
15-3 = ...

Answer 10

12

Answer 11

so lets put everything together

(3x^4 + 9x^3 – 7x + 15) + (–6x^4 – 8x^2 + 5x – 3)

\(\Huge 3x^4-6x^4 = -3x^4\)
\(\LARGE \color{red}{ 9x^3}\)
\(\Large -8x^2\)
\(-7x+5x = -2x \\15-3=12\)

\(\implies -3x^4-8x^2 -2x+12\)
any doubts?

Answer 12

Got it :)