Answer:
x = 75°
Step-by-step explanation:
Sum of angles in a triangle: 180°
So,
50°+55°+x=180°
105°+ x = 180°
Subtract 105° from both sides
x = 75°
Answer:
x^3+5x^2+16x+80
Step-by-step explanation:
You know that you can write your polynom this way : (x-r1)(x-r2)(x-r3) with r1,r2 and r3 the roots so you get :
(x+5)(x+4i)(x-4i)
Simplify (x+4i)(x-4i) with the formula (a-b)(a+b)=a²-b²
so you have (x^2+16)=(x+4i)(x-4i)
Your polynom looks like this :
(x^2+16)(x+5) just expand it
and you get x^3+5x^2+16x+80
Hey that’s the answer I got I hope it helps you.
