In a triangle, the second angle is twice the measure of the first, and the third angle is three times the measure of the second. find the measure of the third angle. a.20 b.30 c.120 d.180

To solve this, I set angle one as x, since we don't know the value of it yet. Angle 2 is twice the first, I made it 2x, and made the third 3x by the same logic. We know that a triangles angles add up to 180 degrees. This means we can make the equation x+2x+3x=180. This simplifies to 6x=180 and so we get the answer that the first angle is 30 degrees.

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

step-by-step explanation:

a'(12.5,11.25)

slope=(y1-y2)/(x1-x2)