(5x^2-7)-(-4x^2+6x-3)

5x^2-4+4(x^2)-6x

Step-by-step explanation:

first you need to remove the unnecessary parentheses it should look like this: 5x^2-7-(4(x^2)+6x-3)

then you should calculate the sum it should look like this: 5x^2-4+4(x^2)-6x and that is your answer

Complementary angles = 90°
x= angle 1
(90-x)= angle 2

Subtract the two angles to get the difference between them (18°).

(90-x) - x= 18
combine like terms

90 - 2x= 18
subtract 90 from both sides

-2x= -72
divide both sides by -2

x= 36° angle 1

Substitute answer in to find angle 2:
=90 - x
=90 - 36
=54° angle 2

Hope this helps! :)