How do you solve 105x+4dx?

1 Answer
Jan 17, 2017

3815

Explanation:

We need to use a u-substitution to solve this question.

STEP 1: Identify the u
u=5x+4

STEP 2: Find du
du=5dx

STEP 3: Change the x-bounds to u-bounds
x=0u=5(0)+4=4
x=1u=5(1)+4=9

STEP 4: Do the u-substitution
105x+4dx
=94u15du
remember: we found du=5dx, so if we solve for dx we get dx=15du
=1594udu
=15[23u32]94
=215[u32]94
=215(3323)
=215(19)
=3815