One reason would be if you did not know the answer so you could do
4-5=x
another reason would be if the problem gave you the answer but not one of the things to get the answer
4-x=-1
not sure if that is what you want but I hope this helped
Answer:2 5/6
Step-by-step explanation:
i used photomath :)
Answer:
if you meant x times y...
15 x 20 is 300.
if you meant x + y...
15 + 20 is 35.
if you meant anything else, please let me know
the way it was written confused me but I tried.
Answer:
14/45
Step-by-step explanation:
So we have the fraction:

We can do this algebraically. Follow to following steps:
Let's let this number equal to n. Thus:

Since there is only 1 digit repeating, let's multiply everything by 10. So:

Now, subtract n from both sides:

On the left, substitute the number for n. On the right, combine like terms:

All of the 1s will cancel. So:

Subtract:

Divide both sides by 9:

Remove the decimal by multiplying both sides by 10:

Reduce:

And we're done!
Use a calculator to check:

Answer:we multiply by the reciprocal of a fraction when completing a division problem because it is a rule in mathematics that when you divide two fraction, you change the division sign to multiplication and flip the fraction at the right of the multiplication sign.
Step-by-step explanation:
For example if you have 4÷ 1/2. It basically means how many 1/2 can one get in 4. And the answers is 8.
Therefore multiplying by the reciprocal of a fraction when completing a division problem is a short cut method that has been tested and proven to be correct.