Question

If m - n = 32 and 3m - 8n - 6 = 0, then 4m - 9n =

Answer 1

m - n = 32
m - 32 = n

so plug in m - 32 in for n in this equation : 3m - 8n - 6 = 0
3m - 8(m - 32) - 6 = 0 -- distribute
3m - 8m + 256 - 6 = 0
-5m + 250 = 0
-5m = -250
m = -250/-5
m = 50

m - n = 32
50 - n = 32
50 - 32 = n
18 = n

check..
3m - 8n - 6 = 0
3(50) - 8(18) - 6 = 0
150 - 144 - 6 = 0
150 - 150 = 0
0 = 0 (correct)

so we know that m = 50 and n = 18
now we sub
4m - 9n =
4(50) - 9(18) =
200 - 162 =
38