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"#
