19. The second angle of a triangle is twice the first. The third angle is 20 more than the first. What is the measure of the first angle

2x+x+x+20=180

Step-by-step explanation:

Triangle Sum Theorem

first angle:x

Second: 2x

Third:x+20

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18

80x^8−68x^6+16^5−20x^4−4x^3+8x^2

hope i'm right lol