As 7 is a constant, it is not affected by the integration, so you can do this:
or if you like to think of it this way:
You multiply by the derivative, but don't forget to divide it.
For this one, I'll take the 7 out again and use the substitution u = 4x + 2. du = 4 dx.
You need a 4 on top, so multiply by .
Since 1/4 is a constant, I took it out like I did with the 7. (Note: only constants that are multiplied or divided can be taken out, addition or subtraction of constants are integrated.)
(since du = 4dx; u = 4x+2)
=