Solve the equation 3 + x/-2 =10

Can someone answer this question? : )

If f(x) = x+8 and g(x) = 4x- 3, find (f+g)(x)

Money off coupons have been circulated to 300 households. only 2/5 of these were redeemed (used) in the local supermarket to get a free shampoo. what fraction of coupons were unused? (ps: write how you got the answer)