Which is the best first step and explanation for solving this system of equations?
2x+3y-(2x)=7-(4y-5)
Subtract the second equation from the first equation.
6x + y = 21
Multiply both sides of the first equation by 3.
2x + 3y = 7
2x = 4y-5
2x+3y + 2x = 7+ 4y-5
Add the two equations to one another.
2x+3y-5-7-5
Subtract an equal amount from both sides of the first equation.