Can anyone help with 11-15?

Will give brainliest sum of arithmetic series (sigma notation) find the numerical answer to the summation given below. (image shown below)

Read the following two statements. then use the law of syllogism to draw a conclusion. if the tv is too loud, then it will give me a headache. if i have a headache, then i will have to rest.

If f(x) =3x-2 and g(x) =2x+1 fins (f+ g) (x)