I need to know the answers to these please

Find least common multiple of 8 and 10.
The answer is 40.

7/8=x/40. We had to multiply 8 by 5 to get 40.

Whatever you do to denominator you must do to numerator. Multiply 7 and 5 to get 35.

Now we have 7/8 is equal to 35/40.

Next, for the 9/10 part. We multiplied 10 and 4 to get 40 so multiply the numerator by 4 as well and you get 36.

Now we have 9/10 is equal to 36/40

The problem is now 35/40 and 36/40

35/40 < 36/40

Which is the same as

7/8 < 9/10