Question

Solve the following system by substitution. m+n=5 and 5m+5n=25. Solve.​

Answer 1

Infinitely many solutions (x ∈ R)

Explanation:

`\left\{\begin{array}{ccc}m+n=5&\text{subtract}\ n\ \text{from both sides}\\5m+5n=25\end{array}\right\\\\\left\{\begin{array}{ccc}m=5-n&(1)\\5m+5n=25&(2)\end{array}\right\qquad\text{put (1) to (2):}\\\\5(5-n)+5n=25\qquad\text{use the distributive property}\\\\(5)(5)+(5)(-n)+5n=25\\\\25-5n+5n=25\qquad\text{cancel}\ 5n\\\\25=25\qquad\bold{TRUE}`