Obtuse, acute, and right.
80% of 20 is 80/100 x 20 = 16
So, kelly has used 16 stamps, and has 4 left
3(x)-10=x+4. That’s the equation. Ight, now we gotta solve it. It would be 3x-10=x+4, then you subtract 4 from each side, so 3x-14=x, then subtract 3x, so -2x=-14, then divide -2x by -2 and -14 by 2, which means the answer is x=-7. Thank me later.
Answer:
b=(-10-a)/4
First factor out the common number:3
Then divide both sides by 3
Then simplify 30/3 to 10
Then subtract a to get your answer