SOLUTION: 5a+3b=11 -2a+3=b What is the value of b for the solution

Algebra ->  Customizable Word Problem Solvers  -> Numbers -> SOLUTION: 5a+3b=11 -2a+3=b What is the value of b for the solution       Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 884052: 5a+3b=11
-2a+3=b
What is the value of b for the solution

Answer by cigany29(23) About Me  (Show Source):
You can put this solution on YOUR website!
You are told that b=-2a+3
f(x)=5a+3b=11
g(x)=-2a+3
%28fog%29%28x%29=5a%2B3%28-2a%2B3%29=11
So in your first equation, substitute -2a+3 for b.

5a%2B3b=11
5a%2B3%28-2a%2B3%29=11
5a-6a%2B9=11
-a%2B9=11
-a=2
a=-2
Now sub your found value of a into the equation to find b.
b=-2a%2B3
b=-2%28-2%29%2B3
b=4%2B3
b=7
You can check this by substituting your values for a and b back into your first equation
5a%2B3b=11
5%28-2%29%2B3%287%29=11
-10%2B21=11
11=11