Chris is incorrect. To check the answer, replace m with 8 and simplify the left side. So m/6 turns into 8/6 which converts to the decimal value 1.333 (use a calculator)
Therefore the original equation m/6 = 48 becomes 1.333 = 48 after you plug in m = 8 and simplify fully. The two sides of 1.333 = 48 are not the same, so m = 8 is not the solution.
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The solution is actually 288 and we can prove it so like this
m/6 = 48
288/6 = 48 .... replace m with 288
48 = 48 .... use a calculator to compute 288/6
So the solution m = 288 is confirmed
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How did I get this answer? By multiplying both sides by 6
m/6 = 48
6*(m/6) = 6*48 ..... multiply both sides by 6
m = 288
So Chris mistakenly divided both sides by 6, which explains how he got 48/6 = 8 as the solution. Instead he should have multiplied both sides by 6. This is to undo the operation "divide by 6" that is being applied to m in the original equation.