Answer:
Angle GHI measures 56º, and angle JKL measures 34º.
Step-by-step explanation:
Complementary Angles:
If two angles are complementary, the sum of their measures is 90º.
∠GHI is (5x+6)∘ and ∠JKL measures (3x+4)∘.
Since they are complementary:






Measures:
GHI: 5*10 + 6 = 50 + 6 = 56º
JKL: 3*10 + 4 = 30 + 4 = 34º.
Angle GHI measures 56º, and angle JKL measures 34º.
A positive
as there are 4 negetive multiplied
We are given that there are a total of 78 students. If we set the following variables:

Then, the sum of all of these must be 78, that is:

Since there are 15 in chemistry and physics and 47 in chemistry, we may replace that into the equation and we get:

Simplifying:

Now we solve for P by subtracting 62 on both sides:

Therefore, there are 16 students in physics