SOLUTION: How do I solve this system of equations using multiplication and addition method? a/6 + b/4=5/2 2a/3 - b/2=-2 Hope you can understand this

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Question 140980This question is from textbook Prentice Hall Algebra 1
: How do I solve this system of equations using multiplication and addition method?
a/6 + b/4=5/2
2a/3 - b/2=-2
Hope you can understand this This question is from textbook Prentice Hall Algebra 1

Answer by jojo14344(1513) About Me  (Show Source):
You can put this solution on YOUR website!
Sure!
Let's simplify 1st this eqn:
a/6 + b/4=5/2
a=(5/2 - b/4)/6
a= 30/2 - 6b/4
a= 15 - 3b/2 ------ mark eqn 1. oks
Now, this value of "a" we substitute it to the other eqn but first let simplify it,
2a/3 - b/2=-2 ----- mark eqn 2 oks
becomes,
b/2=2a/3 +2 , and we subsitute "a" as shown in eqn 1 here.
So, b/2= 2(15 -3b/2)/3 +2
b/2 = [2(30 - 3b)/2]/3 +2
b/2 (30-3b)/3 +2
b/2= (30-3b+6)/3
3b=60-6b+12
3b+9b=72
b=8
For "a", go back eqn 1: a=15 - 3(8)/2=15-12
a=3
In doubt? Simply go back to your eqn 2 to check,
2(3)/3 - (8/2) =-2
2-4=-2
-2=-2, cool!
Thank you,
Jojo