The change from 3/4 to 4/10 is found by obtaining and applying the LCD:
15/20 to 8/20 is a negative change, and the amount of the change was -7/20.
We compare this result to the original value, 15/20, to obtain the percentage change in the fraction:
-7/20
----------- = -7/15 = -0.467 => -46.7%
15/20
-8+4x=-20x-25+7x
4x+20x-7x=-25+8
17x=-17 /17
x=-1
combine like terms
-6<-1x
divide by negative 1 on both sides
flip the sign when dividing by a negative number
6>x is the answer.
B=A-6
A+B=22
substitute: A+(A-6)=22 =>A=14
B=14-6=8
8 years later, Amy will be 22, Bill will be 14
