Question

Solve by substitution method:

7m +n =46
m-3n=16

Answer 1

7m + n = 46 ----(x)
m - 3n = 16 ----(xx)
multiply eq (xx) by 7 and subtract it from (x).
7m + n = 46
7m - 21n = 112
-_____________
22n = -66

n = -66/22 = -3
n = -3
put the value of n in any of the above eq say (x)
7m + (-3) = 46
7m - 3 = 46
7m = 46 + 3 = 49
m = 49/7 =7
m = 7