Answer:
D
Step-by-step explanation:
Let's focus on the given equation. The C represents the cost, while the x must be the number of tacos, which is what we're solving for. Since we're given the boundary that C must be 300, then the solution would be:
300 = x² - 40x + 610
x² - 40x + 310 = 0
Apply the quadratic formula where a = 1, b = -40 and c = 310. The roots of x are:
x = 29.49≈30
x = 10.51≈11
<em>Thus, she needs to sell either 30 or 11 tacos.</em>
The answer is 26 divided by 2 witch is 13
Let's say that y is the unknown
180=2x+3+5x+1+y
180=7x+4+y
180-7x-4=y
176-7x=y=third angle

so,

it equals 12.49 or 12.5 depending on rounding
I hope this helps!