N=15. Equation: You need to isolate N. Multiply both sides by 300 to get 300/20 = N. You can simplify it to 15.
B. Multiply by 100, remember it by moving the decimal over to the left 2 places
The vertical angle is right across so it would be <DGC
Start by finding a common denominator.
In this case, it would be 21.
So, -12/21 + -28/21= -40/21
