What is the solution to the system of equations?

y = 1.5x – 4

y = –x

Red line for y=1.5x-4 
and blue for y= -x

the solution is (1.6  , -1.6)

X=1.6, y=-1.6
using substitution,
(replace y in equation 1 with -x from equation 2)
-x=1.5x-4
(make all variables on the same side- subtract 1.5x)
-2.5x=-4
(divide by -2.5 to get x by itself)
x=1.6
(plug x into the second equation to solve for y)\
y=-1.6

This polygon has 4 sides
180(4-2) = 180(2) = 360 degree
80+90+2x + 3x = 360
170+5x = 360
5x = 190
x= 38
measure of angle t is 2(38)= 76
the answer is c. trust me
hope this !