Given that quadrilateral QRST is a square.
Each angle of a square is of 90 degrees.
Angle <RQT is also an angle of 90 degrees.
We also given angle RQT = 3x - 6.
So, we can setup an equation as 3x-6 =90.
Now, we need to solve the equation for x.
6 is being subtracted from left side.
We always apply reverse operation. Reverse operation of subtraction is addition.
So, adding 6 on both sides of the equation, we get
3x-6+6 =90+6.
3x = 96.
3 is being multipied with x, in order to remove that 3, we need to apply reverse operation of multiplication.
So, dividing both sides by 3.

x=32 (final answer).
Answer: 12 friends.
Step-by-step explanation:
the data we have is:
Mei Su had 80 coins.
She gave the coins to her friends, in such a way that every friend got a different number of coins, then we have that:
The maximum number of friends that could have coins is when:
friend 1 got 1 coin
friend 2 got 2 coins
friend 3 got 3 coins
friend N got N coins
in such a way that:
(1 + 2 + 3 + ... + N) ≥ 79
I use 79 because "she gave most of the coins", not all.
We want to find the maximum possible N.
Then let's calculate:
1 + 2 + 3 + 4 + 5 = 15
15 + 6 + 7 + 8 + 9 + 10 = 55
now we are close, lets add by one number:
55 + 11 = 66
66 + 12 = 78
now, we can not add more because we will have a number larger than 80.
Then we have N = 12
This means that the maximum number of friends is 12.
Option "D" would be your answer.
- KJ, JL, LK
In mathematical form, it would be: 2x ≥ 40
x ≥ 20
Hope this helps!
F(-3) would be -8, because you would use the first equation. f(2) would be 4 apparently cause theres no x after the 4, or in the equation of the 4. Hope this helps. Please rate, leave a thanks, and mark a brainliest answer(not necessarily mine). Thanks, it really helps! :D