Answer:
4
Step-by-step explanation:
g(f(-9))=4
This is a composite function so we need to first find the value of the function on the inside in order find the value of the composite function
f(-9)=x+7=-9+7=-2
we can put -2 instead of f(-9) in the composite function
g(-2)=(-2)^2=4
the one you have selected is correct
20cm
pythagorean theorem
15^2 + b^2 = 25^2
225 + b^2 = 625
b^2 = 400
b = 20
