The 30/60/90 right triangle is the biggest cliche in trig. We recall the sides come in ratio 

First x:


Next y:


Choice C
The x terms add up to 4x and the numbers add up to 12
4x + 12 = 4(x + 3)
Its C
X+4x=35-20. 5x=35-20. 5x=15. X=3
Answer:
i think it would be B bc its not A or C
Step-by-step explanation:
Step-by-step explanation:
x + y = 3 ---------------- eqn 1
y = -6x + 3 ------------- eqn 2
Substitute y for -6x + 3 in equation 1
x + -6x + 3 = 3
x - 6x + 3 = 3
-5x + 3 = 3
Collect like terms
-5x = 3 - 3
-5x = 0
Divide both sides by -5
x = 0
Hope this helped!