Answer:

Step-by-step explanation:
Given
, start by squaring both sides to work towards isolating
:

Recall
and
:

Isolate the radical:

Square both sides:

Expand using FOIL and
:

Move everything to one side to get a quadratic:

Solving using the quadratic formula:
A quadratic in
has real solutions
. In
, assign values:

Solving yields:

Only
works when plugged in the original equation. Therefore,
is extraneous and the only solution is 
Answer:
48,000,000
Step-by-step explanation:
47,709,982
Look at the millions place and then see if the number after that is a greater number than 4. If it isn't, round down but if it is, round up
Answer:
1.)21°
2.)51°
3.)73°
4.)50°
Step-by-step explanation:
1.) 90° - 69°
= 21°
2.) 90° - 39°
= 51°
3.) 90° - 17°
= 73°
4.) 90° - 40°
= 50°
Wouldn't r = -10?
because you'd multiply -7 by 3, to get rid of the division.
then you'd add 11.