Suppose A and B represent linear expressions. If A+ B=2x -2 and A -B=4x-8, how do you find A and B?
1 Answer
Feb 21, 2018
Explanation:
A+B=2x-2to(1)
A-B=4x-8to(2)
(1)+(2)" term by term to eliminate B"
(A+A)+(B-B)=(2x+4x-2-8)
rArr2A=6x-10
"divide both sides by 2"
rArrA=1/2(6x-10)=3x-5
"substitute "A=3x-5" in equation "(1)
3x-5+B=2x-2
"subtract " (3x-5)" from both sides"
rArrB=2x-2-3x+5=3-x
color(blue)"As a check"
A-B=3x-5-3+x=4x-8" correct"
