Wouldn’t 18 be 135? I need help with the second one as well.

Question 18= 135, Question 19= 540

Step-by-step explanation:

Hello there! So you were right for number 18! It is for sure 135. This is because these are alternate exterior angles which are always congruent(the same).

Number 19 is confusing however. So a pentagon is a 5 sided shape as we know. From a vertex that we will call A, we can draw two diagonals which will then separate it into triangle. 3 of them to be exact.

We are trying to find the sum of all the interior angles and we know that a triangle has a sum of 180 degrees, so since there are three, we multiple it by three.

We then get 540 degrees.

Hope this helped! Sorry if I didn’t explain it well! :(

what graph

step-by-step explanation:

{x = -1/2 ,   y = -1

step-by-step explanation:

solve the following system:

{2 x + y = -2

{10 x - 3 y = -2

in the first equation, look to solve for y:

{2 x + y = -2

{10 x - 3 y = -2

subtract 2 x from both sides:

{y = -2 x - 2

{10 x - 3 y = -2

substitute y = -2 x - 2 into the second equation:

{y = -2 x - 2

{10 x - 3 (-2 x - 2) = -2

10 x - 3 (-2 x - 2) = (6 x + 6) + 10 x = 16 x + 6:

{y = -2 x - 2

{16 x + 6 = -2

in the second equation, look to solve for x:

{y = -2 x - 2

{16 x + 6 = -2

subtract 6 from both sides:

{y = -2 x - 2

{16 x = -8

divide both sides by 16:

{y = -2 x - 2

{x = -1/2

substitute x = -1/2 into the first equation:

{y = -1

{x = -1/2

collect results in alphabetical order:

answer:   {x = -1/2 ,   y = -1