look to cancel things. start off just from the top and bottom of the two fractions.

you'll see:

so now you're left with:

now you can do some cross canceling:

so you're left with:

no more canceling you can do. so just multiply out the top and bottom of the fraction.

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Get rid of that fraction on the right.

Just simply multiply by :

Now just multiply the left hand side and get it equal to zero.

Then you're solving for m like a normal quadratic problem.

Keep in mind that m cannon be - 4 as it would make the bottom of the fraction zero in the original problem.