Answer:
A= 150°
B=30°
C=150°
Step-by-step explanation:
Since a line is 180°, you can write an equation for C. C+30°=180° , from here use algebra to find C. The value of C will be 150°. When the value of C is 150° , since they're supplementary angles, the value of A will also be 150°.
Important thing to note:
The value of all these angles combined together is 360°.
The answer should be positive 5 or 5

Negative multiply negative = Positive
Negative multiply positive = negative

Thus the answer is -4a + 16b - 12c - 12d.
Complementary angles, sum = 90
So 3y - 4 + 73 = 90
3y + 69 = 90
3y = 21
y = 7
Answer
y = 7