When solving a multivariable equation for a particular variable, we sometimes have to factor some terms in the equation to reach the solution.

For example, let's solve the following equation for the variable d\mathbin{:}

2cd - 3d = 5

First, we factor out d in the expression on the left-hand side. This gives

d(2c-3) = 5.

Then, we divide both sides of the equation by (2c-3) to isolate d\mathbin{:}

\begin{align*} \require{cancel} d(2c-3) &= 5\\[5pt] \dfrac{d(2c-3)}{2c-3} &=\dfrac{5}{2c-3} \\[5pt] \dfrac{d\cancel{(2c-3)}}{\cancel{2c-3}} &=\dfrac{5}{2c-3} \\[5pt] d &= \dfrac{5}{2c-3} \end{align*}

Note: This result assumes that 2c-3\neq 0.

FLAG

Solve the equation 2 = wz - 2w +1 for the variable w.

EXPLANATION

We need to isolate all terms with w on one side of the equation. To do this, we subtract 1 from both sides:

\begin{align*} 2 &= wz - 2w +1 \\[5pt] 2-1 &= wz - 2w +1-1\\[5pt] 1 &= wz - 2w \end{align*}

Next, we factor out w in the expression on the right-hand side.

\begin{align*} 1 &= wz - 2w \\[5pt] 1 &= w(z-2)\\[5pt] \end{align*}

Then, we divide both sides by (z-2) to isolate w\mathbin{:}

\begin{align*} \require{cancel} 1 &= w(z-2) \\[5pt] \dfrac{1}{z-2} &= \dfrac{w(z-2)}{z-2} \\[5pt] \dfrac{1}{z-2} &= \dfrac{w\cancel{(z-2)}}{\cancel{z-2}} \\[5pt] \dfrac{1}{z-2} &= w \\[5pt] w &= \dfrac{1}{z-2} \end{align*}

Note: This result assumes that z-2\neq 0.

FLAG

If $2kx - x= 1,$ then $x=$

a
$\dfrac{1}{2k}$
b
$2k-1$
c
$ \dfrac{1}{2k+1}$
d
$2k+1$
e
$ \dfrac{1}{2k-1}$

If $5 = 3pq - p,$ then $p = $

a
b
c
d
e

If $2mn +m + 4= 7,$ then $m = $

a
b
c
d
e

Solve the equation 4ky=5y + 1 for the variable y.

EXPLANATION

We need to isolate all terms with y on one side of the equation. To do this, we subtract 5y from both sides:

\begin{align*} \require{cancel} 4ky &= 5y + 1 \\[5pt] 4ky - 5y &= 5y + 1 - 5y \\[5pt] 4ky -5y &= 1 \end{align*}

Notice that all terms containing y are on the left-hand side, and all terms independent of y are on the right-hand side.

Next, we factor out y in the expression on the left-hand side.

\begin{align*} 4ky -5y &= 1 \\[5pt] y(4k -5) &= 1 \end{align*}

Finally, we divide both sides by (4k -5) to isolate y\mathbin{:}

\begin{align*} \require{cancel} y(4k-5) &= 1 \\[5pt] \dfrac{y(4k-5)}{(4k-5)} &= \dfrac{1}{(4k-5)} \\[5pt] \dfrac{y\cancel{(4k-5)}}{\cancel{(4k-5)}} &= \dfrac{1}{4k-5} \\[5pt] y &= \dfrac{1}{4k-5} \end{align*}

Note: This result assumes that 4k-5\neq 0.

FLAG

If $3xc = 5-2x,$ then $x=$

a
$\dfrac{5}{3c+2}$
b
$15c+10$
c
$\dfrac{3c+2}{5}$
d
$\dfrac{5}{c}$
e
$\dfrac{1}{15c+10}$

If $3xy - 4= 7y+2,$ then $y=$

a
b
c
d
e

If $2mn + 3 = n- 3m,$ then $m = $

a
b
c
d
e

Solve the equation \dfrac{xy}{3} = \dfrac{y - 1}{2} for the variable y.

EXPLANATION

We need to isolate all terms with y on one side of the equation. To do this, we first cross-multiply:

\begin{align*} \dfrac{xy}{3} &= \dfrac{y - 1}{2} \\[5pt] 2\cdot xy &= 3 \cdot (y - 1) \\[5pt] 2xy &= 3y - 3 \end{align*}

Next, we subtract 3y from both sides of the equation:

\begin{align*} 2xy &= 3y - 3 \\[5pt] 2xy - 3y &= 3y - 3 - 3y \\[5pt] 2xy - 3y &= - 3 \\[5pt] \end{align*}

Notice that all terms containing y are on the left-hand side, and all terms independent of y are on the right-hand side.

Then, we factor out y from the left-hand side:

\begin{align*} \require{cancel} 2xy - 3y &= - 3 \\[5pt] y(2x - 3) &= - 3 \end{align*}

Finally, we divide both sides by (2x - 3) to isolate y\mathbin{:}

\begin{align*} y(2x - 3) &= -3 \\[5pt] \dfrac{y(2x - 3)}{2x - 3} &= \dfrac{-3}{2x - 3} \\[5pt] \dfrac{y\cancel{(2x - 3)}}{\cancel{2x - 3}} &= \dfrac{-3}{2x - 3} \\[5pt] y &= -\dfrac{3}{2x - 3} \\[5pt] \end{align*}

Note: This result assumes that 2x-3\neq 0.

FLAG

If $\dfrac{5pq}{2}=\dfrac{4p+q}{3},$ then $p = $

a
b
c
d
e

If $\dfrac{km-1}{2}=\dfrac{m+4}{3},$ then $m = $

a
b
c
d
e
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