I need help on Canceling out division. I know u have to undo it by multiplying it to the other side of the equation. Like n/7=11 n=77. But how would u do it on like for example n/7=x/11. Do you multiply 7 to both x and 11 or just 11??

Question

whpalmer4 · Answer

$$\frac{n}{7} = \frac{x}{11}$$Multiply both sides by 7:
$$\frac{7n}{7} = \frac{7x}{11}$$Multiply both sides by 11:
$$\frac{7*11n}{7} = \frac{11*7x}{11}$$Cancel common factors
$$11n=7x$$

whpalmer4 · Answer

If you multiply both sides of the equation by the product of all of the denominators, all the fractions go away.  That may be a larger number than you need to use, but it will always work.  The smallest number that will work is the LCM or least common multiple of all the denominators.

anonymous · Answer

So u only mutiplu it to the numerators not denominators ?

whpalmer4 · Answer

In that particular equation, you could also solve by cross multiplying:
$$\frac{n}{7} = \frac{x}{11}$$$$11n = 7x$$

Multiplying the numerators is sufficient.  Just remember to multiply everything!