Answer:
x = 16.5
Step-by-step explanation:
Use pythagorean theorem
a² + b² = c²
Plug in terms
7.1² + x² = 18²
Square each term
50.41 + x² = 324
Subtract a from c
x² = 273.59
Find square root
16.5
Answer: 11/15
f(3) = 63
f(x) = 4^x-1;
Let x =3
f(3) = 4^3 -1
= 64-1
=63
11 feet
