Question

Solve the following equation to get y by itself:
4y + 2z = 20

Answer 1

To isolate y, we first subtract 2z from both sides


\[\Large 4y + 2z = 20\]


\[\Large 4y + 2z{\color{red}{-2z}} = 20{\color{red}{-2z}}\]


\[\Large 4y + 0z = 20-2z\]


\[\Large 4y + 0 = 20-2z\]


\[\Large 4y = 20-2z\]


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Then we divide both sides by 4 to fully isolate y


\[\Large 4y = 20-2z\]


\[\Large \frac{4y}{{\color{blue}{4}}} = \frac{20-2z}{{\color{blue}{4}}}\]


\[\Large y = \frac{20-2z}{4}\]


\[\Large y = \frac{-2z+20}{4}\]


\[\Large y = \frac{-2(z-10)}{2*2}\]


\[\Large y = \frac{-\cancel{2}(z-10)}{\cancel{2}*2}\]


\[\Large y = -\frac{z-10}{2}\]