Answer:
it would be 59 miles per hour
Step-by-step explanation:

Answer:
= 21x - 1
Step-by-step explanation:
= (4x + 12x) + (5x - 1)
= 4x + 12x + 5x - 1
= 16x + 5x - 1
= 21x - 1
Step-by-step explanation:
take the right triangle
15^2 = 9^2 + x^2
225 = 81 + x^2
x = 12
area of square b = 144