Step-by-step explanation:
Given
One plain pizza and two sodas cost $15.95
Similarly, 3 plain pizzas and 5 sodas cost $45.90
Suppose the cost of single pizza and soda be 
and 
In linear equation format, it can be written as
Therefore, the above two equations represents the given situation.
The basic angle for 1/2 is 60°, and cosines are negative in the first and third quadrant.
So, you take 180° - 60° = 120° to get the angle in the first quadrant, and 180° + 60° = 240° to get the angle in the third quadrant.
Since only 120° is an option, the answer is
B.
Distribute.
(a + 8)(a -3)
FOIL:
First, Outside, Inside, and Last
a * a = a^2
a * 3 = 3a
8 * a = 8a
8 * -3 = - 24
a^2 + 11a - 24
Distributed Expression: a^2 + 11a - 24
A = 180
b = 180
c = 180
180+180-180 = 180
