Can soomeone help me on this one too

70°

Step-by-step explanation:

An euclidean triangle (a triangle on a straight plane) has sum of three angles equal to 180°.

When we talk about a triangle, we usually talk about an euclidean one.

There are also a non-euclidean triangles which are a triangle on circular plane which has sum of angles above 180° and one that is a hyperbolic triangle version which has sum below 180°.

Back to the question, since we know that the triangle is an euclidean one and thus has the sum equal 180°.

x+20+40+2x-30 = 180

Combine like terms:

3x+30=180

Subtract both sides:

3x+30-30=180-30

3x=150

Divide both sides by 3.

3x/3 = 150/3

x = 50

Since we want to find angle B which has measure of 2x-30, substitute x = 50 in 2x-30.

2(50)-30 = 100-30 = 70

Therefore angle B is 70°

need points to ask question

step-by-step explanation:

c.

step-by-step explanation:

because first you have to add the 4x, 9x, and the 7x together and you get 20x and then you add the last numbers up and you get 5and then you put the subtraction sign in there and that's how you get the answer.