Hi help w this pls <3

You got a job selling magazines door-to-door. you are paid $100 per day plus $1.50 for each magazine you sell. which recursive formula models this situation?

The suare root of 9x plus 7 plus the square rot of 2x equall to 7

If f(x)= x^2 - 4 and g(x)=x^2 + 2 x, (b). (f-g)(x) i think i know the 1st 2 steps: f(x)-g(x) x^2-4 - x^2+2x