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45 votes
45 votes
Solve 2x – 2y = 5 for y.

User Biz
by
2.9k points

2 Answers

22 votes
22 votes

Answer:


\large\boxed{\tt y = x - 2.5}

Explanation:


\textsf{We are asked to solve for the value of y.}


\textsf{Because there's 2 variables, and just a whole number on the right side of the}


\textsf{equation, it's impossible to find the exact value of y. For finding y, it has to involve}


\textsf{using the rest of the values where we subtract the right side of the equation by}


\textsf{the left side, excluding the variable we are trying to find. This is called \underline{Isolation}.}


\large\underline{\textsf{What is Isolation?}}


\textsf{Isolation in Mathematics is isolating a certain term to find the value of what's asked.}


\textsf{Isolation is commonly used to find variables, where we use the \underline{Properties of Equality}}


\textsf{to find what's missing.}


\large\underline{\textsf{What are the Properties of Equality?}}


\textsf{Properties of Equality are properties that allow us to manipulate one side of the}


\textsf{equation, which we have to do the same for the other side which says both expressions}


\textsf{are equal to each other.}


\large\underline{\textsf{Solving;}}


\textsf{We will Isolate y by using the \underline{Properties of Equality.}}


\tt 2x-2y=5


\textsf{To isolate y, we should use the \underline{Subtraction Property of Equality} where we subtract}


\textsf{the same term from both sides of the equation, which states that both expressions}


\textsf{will still be equal to each other.}


\underline{\textsf{Subtract 2x from both sides of the equation;}}


\tt 2x-2x-2y=-2x+5


\tt -2y = -2x+5


\textsf{Remember that we are asked for the value of y, which means that y shouldn't have}


\textsf{any coefficients. We want to remove that coefficient by using the \underline{Division Property}}


\textsf{\underline{of Equality} to divide both sides of the equation by -2.}


\underline{\textsf{Divide both sides of the equation by -2;}}


\tt (-2y)/(-2) = (-2x+5)/(-2)


\large\boxed{\tt y = x - 2.5}

User Serraosays
by
3.0k points
19 votes
19 votes

Hi!

To solve this for y, we want to isolate the y variable on one side of the equation.

Given:


2x-2y=5

Add 2y to both sides:


2x=5+2y

Subtract both sides by 5:


2x-5=2y

Divide both sides by 2:


(2x-5)/(2) =y

User Chris Sienkiewicz
by
3.4k points