Answer:
x = 12
Step-by-step explanation:
The sum of the 3 angles in a triangle = 180°
Sum the 3 given angles and equate to 180, that is
9x + 11 + 3x - 15 + 2x + 16 = 180, simplify left side
14x + 12 = 180 ( subtract 12 from both sides )
14x = 168 ( divide both sides by 14 )
The solution is (-10,-7)
y=2/5x-3 and x=-10
We know x = -10
Substitute the second equation into the first equation to find y
y = 2/5 (-10) -3
y = -4 -3
y = -7
Let's see
1st one is yes
the other two im not sure about
