Answer:
b=12 or b=-12
Step-by-step explanation:
If the quadratic equation has a double root, then its discriminant is equal to zero. Find the discriminant:
Now equate the discriminant to 0:
y = 55
The sum of the angles of a triangle are 180
40 + y+30 + y = 180
Combine like terms
70 +2y = 180
Subtract 70 from each side
2y = 180-70
2y = 110
Divide each side by 2
2y/2 = 110/2
A