Which is a correct first step for solving this equation?
2x−1(5−3x)=4x+2

I would start by distributing the (-1) through the (5-3x)

2x-5+3x=4x+2
(combine like terms)
5x-5=4x+2
(move the x to the left side of the equation by subtraction)
x-5=2
(then of course we isolate the x by adding the 5 to the right side)
x=7

then you can check your work by replacing all of the x's with 7
2(7)-1(5-3(7))=4(7)+2
14-1(-16)=28+2
14+16=30
30=30

hope this helps!

Agc and bgd are vertical angles

The correct answer is -4