When solving equations that have only one type of variable, you just get the variable on one side and the numbers on the opposite side.
6x + 7 = 8x - 13
Let us get the x on the left side.
Subtract each side of the equation by 8x.
6x + 7 = 8x - 13
-2x + 7 = -13
Subtract 7 from each side of the equation.
-2x = -20
Divide both sides by the coefficient of x. Which is -2.
x = 10
So, x is equal to 10 for this equation.
It would be b or d i hope that help
The second one and the last one
