Bernard solved the equation 5x+(-4)=6x+4 using algebra tiles. Which explains why Bernard added 5 negative x-tiles to both sides in the first step of the solution? A) He wanted to create zero pairs on the left side of the equation to get a positive coefficient of x on the right side. B) He wanted to combine more negative tiles with the 4 negative tiles on the left side of the equation. C) He wanted to remove the larger coefficient on the left side of the equation. D) He wanted to have 10 x-tiles on the left side of the equation.

To find why he would do this, we need to understand what all the possible first steps are in this equation.

You could add 4 to both sides.
You could subtract 4 from both sides.
You could subtract 5x from both sides.
You could subtract 6x from both sides.

Any of these work. In Bernard's case, he added 5 negative x tiles, meaning he subtracted. C and D already make no sense, but allow me to further explain. By him subtracting 5x from both sides, the equation turns into:

-4 = x + 4

By this point, he can just subtract 4 from both sides to find the value of x. But the question asks for why he did the first step. Therefore, it would be A.