math help

What is 30/50 + 3/7?

What is 30/50 + 3/7?

This is how to add

30
50
+
3
7

Step 1

Of course, you can't add two fractions if the denominators (bottom numbers) don't match. To get a common denominator, multiply the denominators together. Then we fix the numerators by multiplying each one by their other term's denominator.

Now you multiply 30 by 7, and get 210, then we multiply 50 by 7 and get 350.

30/50 times 7

Do the same for the second term. We multiply 3 by 50, and get 150, then multiply 50 by 7 and get 350.

3/7 times 50

The problem now has new fractions to add:

210
350
+
150
350

Step 2

Since our denominators match, we can add the numerators.

210 + 150 = 360

This yields the answer

360
350

Step 3

The last step is to reduce the fraction if we can.

To find out, we try dividing it by 2...

Are both the numerator and the denominator evenly divisible by 2? Yes! So we reduce it:

360
350
÷ 2 =
180
175

Let's try dividing by that again...

Nope! So now we try the next greatest prime number, 3...

Nope! So now we try the next greatest prime number, 5...

Are both the numerator and the denominator evenly divisible by 5? Yes! So we reduce it:

180
175
÷ 5 =
36
35

Let's try dividing by that again...

Nope! So now we try the next greatest prime number, 7...

Nope! So now we try the next greatest prime number, 11...

Nope! So now we try the next greatest prime number, 13...

Nope! So now we try the next greatest prime number, 17...

Nope! So now we try the next greatest prime number, 19...

Nope! So now we try the next greatest prime number, 23...

Nope! So now we try the next greatest prime number, 29...

Nope! So now we try the next greatest prime number, 31...

Nope! So now we try the next greatest prime number, 37...

No good. 37 is larger than 36. So we're done reducing.

There you have it! Here's the final answer to 30/50 + 3/7

30
50
+
3
7
=
36
35
© 2014 Randy Tayler