Answer:
15
Step-by-step explanation:
Let's call Leah's age l and Rachel's age r. We can write:
l = 3r - 2 (1)
l + 3 = 2(r + 3) + 7 (2)
Substituting (1) into (2) we get:
(3r - 2) + 3 = 2(r + 3) + 7
3r + 1 = 2r + 13
r = 12
In 3 years Rachel will be 12 + 3 = 15 years old.

Try setting

, so that

. The interval then changes from

to

.
Now, the integral is

The Pythagorean identity lets you reduce the denominator:

Since

for the given interval, you have

, which means the integral is equal to
Answer:
y = 18
Step-by-step explanation:
3.23(y – 18) - 19.17 = -19.17
3.23y - 18 x 3.23 = -19.17 + 19.17
3.23y - 58.14 = 0
3.23y = 58.14
3.23y/3.23 = 58.14/3.23
y = 18