One angle in a triangle measures twice the smallest angle, whereas the largest angle is nine times the smallest angle. Find the measures of all three angles. ° (smallest value)
°
° (largest value)

Step-by-step explanation:

Let the smallest angle be x

2nd angle = 2x

3rd angle = 9x

By angle sum property

x+2x+9x=180°

x=180/12

x=15

Three angles are 15, 30 and 135

x = ±sqrt(10)

step-by-step explanation:

5 - 2x² = -15

subtract 5 from each side

5-5 - 2x² = -15-5

-2x^2   = -20

divide by -2 on each side

-2x^2   /-2= -20/-2

x^2 =10

take the square root on each side

sqrt(x^2 )=±sqrt(10)

x = ±sqrt(10)

check:

5 - 2x² = -15

+sqrt(10)

5 - 2(sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15

-sqrt(10)

5 - 2(-sqrt(10))² = -15

5 -2(10) = -15

5 -20 = -15

-15 = -15