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How do you solve #\frac { 5} { 15} = \frac { x } { 75}#?

Answer 1

Kennedy Adams

#x = 25#

You multiply 75 and 15 on BOTH sides of the equation:

#75 * 5 = 15 * x#

You now divide 15 by BOTH sides to obtain:

#x = (75*5)/15#

which provides the previously stated response.

In school, they teach to just cross multiply, which yields the same equation, but its not clear why you can do that. Now it should be ;) I am emphasizing that you have to do the mentioned operations (multiplication and division) to BOTH sides, as only then will the equality sign still hold true.

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Answer 2

Nathan Axel

To solve the equation (\frac{5}{15} = \frac{x}{75}), you can cross multiply. This means you multiply 5 by 75 and set it equal to 15 times x. So, (5 \times 75 = 15 \times x). Simplify both sides and solve for x. (375 = 15x). Then, divide both sides by 15 to isolate x. So, (x = \frac{375}{15}). Finally, simplify the fraction to get the value of x, which is (x = 25).

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.