Question 70457
M-4N=6
M=4N+6 NOW SUBSTITUTE (4N+6) M IN THE OTHER EQUATION 
3N+5(4N+6)=7
3N+20N+30=7
23N=7-30
23N=-23
N=-23/23
N=-1 ANSWER
M=4*-1+6
M=-4+6
M=2 ANSWER