∫(21x6-e2x-1/x+6)dx
To tackle this question, I would do each part separately.
Firstly, take 21x6...using the product rule this intergrates like so (21/(6+1))x6+1 = (21/7)x7 = 3x7
Second, ekx always intergrates to (1/k)ekx .........so -e2x goes to (-1/2)e2x.
1/x has the common intergral of lnx which must simply be learnt.
And finally, 6 intergrates to 6x.
We then collect all these parts and put them together so we get y=3x7-(1/2)e2x-lnx+6x+C
Always remember that for intergration without limits you must always add C at the end.