Question

When combining like terms, how do I know whether to add or subtract, etc.? For example:

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

Do I add 5x^2 and 7x^2, as well as 7x & 2x?

Please help. I'm overwhelmingly confused. x.x

Answer 1

the sign with 5x^2 is +
the sign in the middle of the brackets is also +
the sign with 7x^2 is +
so yes, you would add 5x^2+7x^2 to get (5+7)x^2.

the sign with -7x is -
the sign in the middle of the brackets is also +
the sign with +2x is +
so, you will do this : -7x+2x = (-7+2)x =... ?

Answer 2

i only factored out 'x' from -7x+2x to get (-7+2)x.
then there will be no confusion whether to add/subtract, just solve the bracket -7+2 =... ?

Answer 3

did you understand ?

Answer 4

by the way ,
\(\huge \color{red}{\text{Welcome to Open Study}}\ddot\smile\)

Answer 5

yes, thank you a lot!