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Solve for a Variable or Formula 1Solve for a Variable or Formula 1
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Question 1 of 5
1. Question
Write `r` as the subject of the equation below`V=pir^2h`Hint
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Changing the subject means operating on an equation so that a chosen variable remains alone on the left side of the equationDivide both sides of the equation by `pih``V` `=` `pir^2h` `V``:pih` `=` `pir^2h``:pih` `V/(pih)` `=` `r^2` `pih:pih` cancels out Get the square root of both sides`V/(pih)` `=` `r^2` `sqrt(V/(pih))` `=` `sqrt(r^2)` `sqrt(V/(pih))` `=` `r` `r` `=` `sqrt(V/(pih))` Interchange the sides `r=sqrt(V/(pih))` 
Question 2 of 5
2. Question
Write `a` as the subject of the equation below`b=(a3)/(a4)`Hint
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Changing the subject means operating on an equation so that a chosen variable remains alone on the left side of the equationMultiply both sides of the equation to `a4``b` `=` `(a3)/(a4)` `b``xx(a4)` `=` `(a3)/(a4)``xx(a4)` `b(a4)` `=` `a3` `1/(a4)xx(a4)` cancels out `ab4b` `=` `a3` Leave only `a` terms on the left`ab4b` `=` `a3` `ab4b` `a` `=` `a3` `a` Subtract `a` from both sides `ab4ba` `=` `3` `aa` cancels out `ab4ba` `+4b` `=` `3` `+4b` Add `4b` to both sides `aba` `=` `4b3` `4b+4b` cancels out Factor out `a``aba` `=` `4b3` `a(b1)` `=` `4b3` Finally, divide both sides by `b1``a(b1)` `=` `4b3` `a(b1)``:(b1)` `=` `(4b3)``:(b1)` `a` `=` `(4b3)/(b1)` `a=(4b3)/(b1)` 
Question 3 of 5
3. Question
Write `x` as the subject of the equation below`73x=mx+t`Hint
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Changing the subject means operating on an equation so that a chosen variable remains alone on the left side of the equationKeep only `x` terms on the right side`73x` `=` `mx+t` `73x` `+3x` `=` `mx+t` `+3x` Add `3x` to both sides `7` `=` `mx+3x+t` `3x+3x` cancels out `7` `t` `=` `mx+3x+t` `t` Subtract `t` from both sides `7t` `=` `mx+3x` `tt` cancels out Factor out `x``7t` `=` `mx+3x` `7t` `=` `x(m+3)` Finally, divide both sides by `m+3``7t` `=` `x(m+3)` `(7t)``:(m+3)` `=` `x(m+3)``:(m+3)` `(7t)/(m+3)` `=` `x` `x` `=` `(7t)/(m+3)` Interchange the sides `x=(7t)/(m+3)` 
Question 4 of 5
4. Question
Write `x` as the subject of the equation below`(1x)/(x+y)=1`Hint
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Changing the subject means operating on an equation so that a chosen variable remains alone on the left side of the equationMultiply both sides to `x+y``(1x)/(x+y)` `=` `1` `(1x)/(x+y)``xx(x+y)` `=` `1``xx(x+y)` `1x` `=` `x+y` `1/(x+y)xx(x+y)` cancels out Leave only the `x` terms on the right side`1x` `=` `x+y` `1x` `+x` `=` `x+y` `+x` Add `x` to both sides `1` `=` `2x+y` `x+x` cancels out `1` `y` `=` `2x+y` `y` Subtract `y` from both sides `1y` `=` `2x` `yy` cancels out Finally, divide both sides by `2``1y` `=` `2x` `(1y)``:2` `=` `2x``:2` `(1y)/2` `=` `x` `2:2` cancels out `x` `=` `(1y)/2` Interchange the sides `x=(1y)/2` 
Question 5 of 5
5. Question
Write `b` as the subject of the equation below`x=(2b)/(3b+y)`Hint
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Changing the subject means operating on an equation so that a chosen variable remains alone on the left side of the equationMultiply both sides to `3b+y``x` `=` `(2b)/(3b+y)` `x``xx(3b+y)` `=` `(2b)/(3b+y)``xx(3b+y)` `x(3b+y)` `=` `2b` `1/(3b+y)xx(3b+y)` cancels out `3bx+xy` `=` `2b` Distribute `x` Leave only `b` terms on the left side`3bx+xy` `=` `2b` `3bx+xy` `xy` `=` `2b` `xy` Subtract `xy` from both sides `3bx` `=` `2bxy` `xyxy` cancels out `3bx` `2b` `=` `2bxy` `2b` Subtract `2b` from both sides `3bx2b` `=` `xy` `2b2b` cancels out Factor out `b``3bx2b` `=` `xy` `b(3x2)` `=` `xy` Finally, divide both sides by `3x2``b(3x2)` `=` `xy` `b(3x2)``:(3x2)` `=` `xy``:(3x2)` `b` `=` `(xy)/(3x2)` `(3x2):(3x2)` cancels out `b=(xy)/(3x2)`
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 One Step Equations – Multiply and Divide 1
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