Divide 636 / 12 which equals 53 ?
So we know that an average is the sum of the scores divided by the number of scores that were added together. In this case we are going to be dealing with 4 tests. So let's say x is the score for our fourth test. We can create this equation:

So then we need to simplify the top:

Then multiply by 4 on both sides to get rid of the denominator:

Then solve for x:

So now we know that Sam needs to score a 67 on the fourth test to have an average score of 50.
Angle d is a vertical angle to the 70° angle meaning that angle d is 70°--to confirm it, line EF is 180° and
180- 40-70= 70° (and 70/2 is 35 which is the measurement for angle e and f bc we know that they are equal)
To find a-- we know now that f is 35, bc a and f are vertical angles, that means a is equal to f...
ANSWER- a is 35° and d is 70°
Because they are math buddies say 2x2=4. You can divide 4÷2 and get your original factor (2)... Sorry if it's wrong I think that's what it means ,hope it helps!