Years
>
Year 8>
Equations>
Change the Subject of an Equation>
Change the Subject of an Equation 2Change the Subject of an Equation 2
Try VividMath Premium to unlock full access
Time limit: 0
Quiz summary
0 of 5 questions completed
Questions:
- 1
- 2
- 3
- 4
- 5
Information
–
You have already completed the quiz before. Hence you can not start it again.
Quiz is loading...
You must sign in or sign up to start the quiz.
You have to finish following quiz, to start this quiz:
Loading...
- 1
- 2
- 3
- 4
- 5
- Answered
- Review
-
Question 1 of 5
1. Question
Write `d` as the subject of the equation below`A=1/2h(c+d)`Hint
Help VideoCorrect
Great Work
Incorrect
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 `2``A` `=` `1/2h(c+d)` `A``xx2` `=` `1/2h(c+d)``xx2` `2A` `=` `h(c+d)` `1/2xx2` cancels out Divide both sides by `h``2A` `=` `h(c+d)` `2A``-:h` `=` `h(c+d)``-:h` `(2A)/h` `=` `c+d` `h-:h` cancels out Finally, subtract `c` from both sides`(2A)/h` `=` `c+d` `(2A)/h` `-c` `=` `c+d` `-c` `(2A)/h-c` `=` `d` `c-c` cancels out `d` `=` `(2A)/h-c` Interchange the sides `d=(2A)/h-c` -
Question 2 of 5
2. Question
Write `x` as the subject of the equation below`G(x+y)=H(x-y)`Hint
Help VideoCorrect
Good Job
Incorrect
Changing the subject means operating on an equation so that a chosen variable remains alone on the left side of the equationDistribute `G` and `H``G(x+y)` `=` `H(x-y)` `Gx+Gy` `=` `Hx-Hy` Leave only `x` terms on the left`Gx+Gy` `=` `Hx-Hy` `Gx+Gy` `-Hx` `=` `Hx-Hy` `-Hx` Subtract `Hx` from both sides `Gx+Gy-Hx` `=` `-Hy` `Hx-Hx` cancels out `Gx+Gy-Hx` `-Gy` `=` `-Hy` `-Gy` Subtract `Gy` from both sides `Gx-Hx` `=` `-Gy-Hy` `Gy-Gy` cancels out Factor out `x` and `y``Gx-Hx` `=` `-Gy-Hy` `x(G-H)` `=` `y(-G-H)` `x(G-H)` `=` `-y(G+H)` Finally, divide both sides by `G-H``x(G-H)` `=` `-y(G+H)` `x(G-H)``-:(G-H)` `=` `-y(G+H)``-:(G-H)` `x` `=` `(-y(G+H))/(G-H)` `(G-H)-:(G-H)` cancels out `x` `=` `(y(G+H))/(H-G)` Multiply `-1` to the numerator and denominator `x=(y(G+H))/(H-G)` -
Question 3 of 5
3. Question
Write `x` as the subject of the equation below`1/z=1/y+1/x`Hint
Help VideoCorrect
Excellent
Incorrect
Changing the subject means operating on an equation so that a chosen variable remains alone on the left side of the equationSubtract `1/y` from both sides`1/z` `=` `1/y+1/x` `1/z` `-1/y` `=` `1/y+1/x` `-1/y` `1/z-1/y` `=` `1/x` `1/y-1/y` cancels out `(y-z)/(zy)` `=` `1/x` Cross multiply`(y-z)/(zy)` `=` `1/x` `x(y-z)` `=` `zy` Finally, divide both sides by `y-z``x(y-z)` `=` `zy` `x(y-z)``-:(y-z)` `=` `zy``-:(y-z)` `x` `=` `(zy)/(y-z)` `(y-z)-:(y-z)` cancels out `x=(zy)/(y-z)` -
Question 4 of 5
4. Question
Solve for `t` given that `v=20`, `u=8` and `a=2``v=u+at`- `t=` (6)
Hint
Help VideoCorrect
Well Done
Incorrect
Changing the subject means operating on an equation so that a chosen variable remains alone on the left side of the equationSubstitute the given values to solve for `t``v` `=` `20` `u` `=` `8` `a` `=` `2` `v` `=` `u+at` `20` `=` `8+2t` Substitute known values `20` `-8` `=` `8+2t` `-8` Subtract `8` from both sides `12` `=` `2t` `8-8` cancels out `12``-:2` `=` `2t``-:2` Divide both sides by `2` `6` `=` `t` `2-:2` cancels out `t` `=` `6` Interchange the sides `t=6` -
Question 5 of 5
5. Question
Solve for `r` given that `a=2` and `S=25``S=a/(1-r)`Write fractions in the format “a/b”- `r=` (23/25)
Hint
Help VideoCorrect
Fantastic
Incorrect
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 `1-r``S` `=` `a/(1-r)` `S``xx(1-r)` `=` `a/(1-r)``xx(1-r)` `S(1-r)` `=` `a` `1/(1-r)xx(1-r)` cancels out Divide both sides of the equation to `S``S(1-r)` `=` `a` `S(1-r)``-:S` `=` `a``-:S` `1-r` `=` `a/S` Leave only `r` terms on the left`1-r` `=` `a/S` `1-r` `-1` `=` `a/S` `-1` Subtract `1` from both sides `-r` `=` `a/S-1` `1-1` cancels out Next, multiply both sides by `-1``-r` `=` `a/S-1` `-r``xx(-1)` `=` `(a/S-1)``xx(-1)` `r` `=` `1-a/S` Finally, substitute the given values to solve for `r``a` `=` `2` `S` `=` `25` `r` `=` `1-a/S` `r` `=` `1-2/25` Substitute known values `r` `=` `25/25-2/25` Convert the whole number to a fraction `r` `=` `23/25` `r=23/25`
Quizzes
- One Step Equations – Add and Subtract 1
- One Step Equations – Add and Subtract 2
- One Step Equations – Add and Subtract 3
- One Step Equations – Add and Subtract 4
- One Step Equations – Multiply and Divide 1
- One Step Equations – Multiply and Divide 2
- One Step Equations – Multiply and Divide 3
- One Step Equations – Multiply and Divide 4
- Two Step Equations 1
- Two Step Equations 2
- Two Step Equations 3
- Two Step Equations 4
- Multi-Step Equations 1
- Multi-Step Equations 2
- Solve Equations using the Distributive Property 1
- Solve Equations using the Distributive Property 2
- Solve Equations using the Distributive Property 3
- Equations with Variables on Both Sides 1
- Equations with Variables on Both Sides 2
- Equations with Variables on Both Sides 3
- Equations with Variables on Both Sides (Fractions) 1
- Equations with Variables on Both Sides (Fractions) 2
- Solve Equations with Variables on Both Sides using the Distributive Property 1
- Solve Equations with Variables on Both Sides using the Distributive Property 2
- Solve Equations with Variables on Both Sides using the Distributive Property 3
- Solve Equations with Variables on Both Sides using the Distributive Property 4
- Equation Word Problems 1
- Equation Word Problems 2
- Equation Word Problems 3
- Equation Word Problems 4
- Equation Word Problems (Age)
- Equation Word Problems (Money)
- Equation Word Problems (Harder)
- Equation Problems with Substitution
- Equation Problems (Geometry) 1
- Equation Problems (Geometry) 2
- Equation Problems (Perimeter)
- Equation Problems (Area)
- Change the Subject of an Equation 1
- Change the Subject of an Equation 2
- Change the Subject of an Equation 3