Question

Does any one know the answer to 28=3m+-7m? I don't know the answer and I tried a thousand times, please help I need the answer to night. Thanks! Please show your work.

Answer 1

I don't 'know' the answer, but I know how to find it.

28 = 3m - 7m

Look at the right side. If it said " 3 cows - 7 cows ", you'd know right away
that they add up to - 4 cows .

Similarly, 3m - 7m = - 4m

So now you have 28 = -4 m

Divide each side by -4 : -7 = m

The 1,001th time is always a charm.