A transformation will have a number

What is the length of the missing leg in this right triangle? 18 mm 24 mm 26 mm 32 mm

F(x) = x2 − 9, and g(x) = x − 3 f(x) = x2 − 4x + 3, and g(x) = x − 3 f(x) = x2 + 4x − 5, and g(x) = x − 1 f(x) = x2 − 16, and g(x) = x − 4 h(x) = x + 5 arrowright h(x) = x + 3 arrowright h(x) = x + 4 arrowright h(x) = x − 1 arrowright

F(x)=x/2-2 and g(x)=2x^2+x-3 find (f+g)(x)