B= 30
a2+b2=c2
72^2+b^2 = 78^2
5184+b^2 = 6084
b2 = 900
b = 30
ANSWER

EXPLANATION
We were given that

varies directly as

We can write this mathematically as,

This implies that,

where k is the constant of variation.

This implies that,


The equation becomes

When

Answer:
2.9 feet
Step-by-step explanation:
ten 2-foot paces
= 10 x 2
= 20 feet
Actual length
= 17.1 ft
Difference
= 20 - 17.1
= 2.9 feet
Hello!
We can solve this algebraically
2x + 5 = 3 + 2(x+1)
Distribute the 2
2x + 5 = 3 + 2x + 2
combine like terms
2x + 5 = 2x + 5
Since both sides of the equation is the same all values of x make the equation true
The answer is A
Hope this helps!