Question

2. Solve using the substitution method. Show your work. If the system has no solution or an infinite number of solutions, state this.
8x – 5y = 3
7x + y = 51

Answer 1

Lets take the second equation and make y the subject.
\[y=51-7x\] Now place this value in the first equation.

\[8x-5(51-7x)=3\]Now solve this equation.
\[8x-255+35x=3\]\[43x=258\]\[x=258/43\]\[x=6\]
Now place this equation in any of the above equations.
Lets put it in the first equation.\[8(6)-5y=3\]\[48-5y=3\]\[48-3=5y\]\[45=5y\]\[45/5=y\]\[y=9\]