Answer:
(a^2+3a+1) -(3a^2+5a+(-6)) =4a^2-2a+7
Explanation:
So, first of all, we can look at the equation and separate them based on the power of each number, and sense we are subtracting, we need to distribute the negative sign all across the second set of numbers.
So, for a^2 we have
a^2-(x) =4a^2
If we subtract a^2 on each side, we get
-(x) =3a^2 but since we don't want a negative, we divide each side by -1 which gives us that the mystery value must equal -3.
x=3a^2
Next, we got to take the second set of like terms
(x)-5a=-2a
We got to add 5a on each side which gives us
x=3a
Finally, we take the last set of like terms
1+-(x) =7
we subtract one from each side to get
-(x) =6
We don't want x to be negative therefore we divide each side by -1 so it will end out
x=-6