Respuesta :

Answer:

D. 90

Step-by-step explanation:

All the angles of a triangle will add up to 180 degrees so we will add up everything we are given and set it equal to 180.

(3x) + (x -15 )+ (2x +15) = 180

combine like terms

6x = 180         Keep in mind that the positive 15 and negative 15 cancel

divide by 5

x= 36

But we arent done! we have to go back and plug in everything in to find the greatest angle

3(30) = 90

(30 - 15) = 15

(2(30) + 15) = 45

so the largest number is 90

Answer: Option D. 90°

Step-by-step explanation:

The sum of angles in a triangle = 180°

3x + (x — 15) + (2x + 15) = 180

Clear the bracket

3x + x — 15 + 2x + 15 = 180

6x = 180

Divide both side by 6

x = 180/6 = 30

Substituting the value of, we have:

3x = 3 x 30 = 90

x — 15 = 30 — 15 = 15

2x + 15 = 2(30) + 15 = 60 + 15 = 75

The greatest angle is 90°