Please explain solution

M<GEF=30

M<DEF=40

Step-by-step explanation:

First you want to solve for x. to do that you put both of the equations together and make it equal to 70 since M<GED=70. so you would get 2x+10+5x-10=70.

when you solve that you get x=10. next you substitute x with 10 in the other equations to solve for the unknown measure angle. So M<GEF=2(10)+10 and M<DEF=5(10)-10. When you solve that you get M<GEF=30 and M<DEF=40. you can check this by adding them together and they add up to 70 which is the M<=GED.

f(x) = x^3 -2x^2 -3x

x( x^2 -2x-3)

x( x^2 +x -3x -3)

x( x(x+1) -3(x+1))

x( x-3)( x+1)

so zeroes are 0, 3,-1

its (2) option