Calculate
1/3(1/4+7/8)

We need to find a common denominator(bottom number) for the fractions. It’s 24.
Now what do we need to multiply 3 by to get 24? 8 so you now multiply 8 by the numerator.
1 8
— x —
3 8
Because 8/8 is 1 and it’s multiplication with another fraction will not change the overall value. Just how it’s shown.
Anyway you get 8/24

How many times does 4 go into 24? 6
So...
1 6
— x —
4 6

=6/24

How many times does 8 go into 24? 3 times.

7 3
— x —
8 3

=21/24

So now the equation becomes
8/24(6/24-21/24)
6 21
— - —
24 24

You only subtract the top because the bottom is equal.
=-15/24
And then
-15 8
—- x —-
24 24
Again, multiply only the top.

You get -120/24

Then, calculate how many times 24 can fully go into 120.
5 full times with nothing left over.
But there was a negative fraction so...
You’re answer is -5

Okay so for every triangle has three angles that always add up to 180 degrees. and to tell the difference between whether they are secure, right or obtuse is that acute: has one angle that is less than 90 degrees. right triangle means there is at least one angle that is exactly 90 degrees. and an obtuse angle has an angle that is bigger than 180 degrees. i’ll do #13 as an example: 13. 40 and 50 so if every triangle has 180 degrees 40+50= 90 degrees then180-90= 90 degrees so the third angle is 90 degrees and because this triangle has a 90 degree angle it means it is a right triangle