x = 77 - 2y
Explanations:2x + 4y - 31 = 123
Collect like terms:
Note that when -31 crosses to the right side of the equality sign, it becomes +31
The equation becomes:
2x + 4y = 123 + 31
2x + 4y = 154
2x crosses to the right side of the equality sign and becomes -2x
4y = 154 - 2x
Divide both sides by 4
[tex]\begin{gathered} \frac{4y}{4}=\text{ }\frac{154-2x}{4} \\ y\text{ = }\frac{154-2x}{4} \end{gathered}[/tex]To solve for x:
The given equation is
2x + 4y - 31 = 123
2x + 4y = 123 + 31
2x + 4y = 154
4y crosses the equality sign to the right and becomes -4y:
2x = 154 - 4y
Divide through by 2, the equation becomes:
[tex]\begin{gathered} \frac{2x}{2}=\text{ }\frac{154}{2}-\frac{4y}{2} \\ x\text{ = }77\text{ - 2y} \end{gathered}[/tex]