math help

What is 7/10 + 7/9?

What is 7/10 + 7/9?

Here's how you add

7
10
+
7
9

Step 1

We still have different denominators (bottom numbers), though, so we need to get a common denominator. This will make the bottom numbers match. Multiply the denominators together first. Now, multiply each numerator by the other term's denominator.

Now we multiply 7 by 9, and get 63, then we multiply 10 by 9 and get 90.

7/10 times 9

Now for the second term. You multiply 7 by 10, and get 70, then multiply 10 by 9 and get 90.

7/9 times 10

This gives us a new problem that looks like so:

63
90
+
70
90

Step 2

Since our denominators match, we can add the numerators.

63 + 70 = 133

That gives us an answer of

133
90

Step 3

Can this fraction be reduced?

First, we attempt to divide it by 2...

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

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

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...

Nope! So now we try the next greatest prime number, 41...

Nope! So now we try the next greatest prime number, 43...

Nope! So now we try the next greatest prime number, 47...

Nope! So now we try the next greatest prime number, 53...

Nope! So now we try the next greatest prime number, 59...

Nope! So now we try the next greatest prime number, 61...

Nope! So now we try the next greatest prime number, 67...

Nope! So now we try the next greatest prime number, 71...

Nope! So now we try the next greatest prime number, 73...

Nope! So now we try the next greatest prime number, 79...

Nope! So now we try the next greatest prime number, 83...

Nope! So now we try the next greatest prime number, 89...

Nope! So now we try the next greatest prime number, 97...

No good. 97 is larger than 90. So we're done reducing.

There you have it! Here's the final answer to 7/10 + 7/9

7
10
+
7
9
=
133
90
© 2014 Randy Tayler