`int4/(4x^2+4x+65)dx`
Take the constant out,
`=4int1/(4x^2+4x+65)dx`
Complete the square for the denominator,
`=4int1/((2x+1)^2+64)dx`
Apply the integral substitution: `u=(2x+1)`
`=>du=2dx`
`=>dx=(du)/2`
`=4int1/(u^2+8^2)((du)/2)`
`=2int1/(u^2+8^2)du`
Now use the standard integral:`int1/(x^2+a^2)dx=1/aarctan(x/a)`
`=2(1/8)arctan(u/8)`
`=1/4arctan(u/8)`
Substitute back `u=(2x+1)` and add a constant C to the solution,
`=1/4arctan((2x+1)/8)+C`
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