SOLUTION: Solve each system by the substitution method..I need help can not understand the process. {{{ x + y = 4}}} {{{ x - y = 5}}}

Algebra ->  Linear-equations -> SOLUTION: Solve each system by the substitution method..I need help can not understand the process. {{{ x + y = 4}}} {{{ x - y = 5}}}      Log On


   

Question 124551: Solve each system by the substitution method..I need help can not understand the process.
+x+%2B+y+=+4
+x+-+y+=+5
Answer by iluvbuilding429(41) About Me  (Show Source):
You can put this solution on YOUR website!
Solved by pluggable solver: SOLVE linear system by SUBSTITUTION
Solve:
+system%28+%0D%0A++++1%5Cx+%2B+1%5Cy+=+4%2C%0D%0A++++1%5Cx+%2B+-1%5Cy+=+5+%29%0D%0A++We'll use substitution. After moving 1*y to the right, we get:
1%2Ax+=+4+-+1%2Ay, or x+=+4%2F1+-+1%2Ay%2F1. Substitute that
into another equation:
1%2A%284%2F1+-+1%2Ay%2F1%29+%2B+-1%5Cy+=+5 and simplify: So, we know that y=-0.5. Since x+=+4%2F1+-+1%2Ay%2F1, x=4.5.

Answer: system%28+x=4.5%2C+y=-0.5+%29.