Years
>
Year 10>
Algebraic Fractions>
Finding the Lowest Common Denominator>
Finding the Lowest Common DenominatorFinding the Lowest Common Denominator
Try VividMath Premium to unlock full access
Time limit: 0
Quiz summary
0 of 6 questions completed
Questions:
- 1
- 2
- 3
- 4
- 5
- 6
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
- 6
- Answered
- Review
-
Question 1 of 6
1. Question
Find the lowest common denominator (LCD) of`6x` and `16x^2`Hint
Help VideoCorrect
Great Work!
Incorrect
The lowest common denominator (LCD) can also be referred to as the least common multiple (LCM).First, decompose each term into its smallest factors.`6x` `:` `2`,`3`, `x` `16x^2` `:` `2`,`2,2,2,``x`,`x` Combine the red terms and multiply to the black ones.`\text(LCD)` `:` `2`,`x`,`3,2,2,2,x` `:` `2``xx``x``xx 3 xx 2 xx 2 xx 2 xx x` Multiply the factors `:` `48x^2` `48x^2` -
Question 2 of 6
2. Question
Find the lowest common denominator (LCD) of`x-3` and `3x+5`Correct
Correct!
Incorrect
The lowest common denominator (LCD) can also be referred to as the least common multiple (LCM).First, look for the factors of the given terms.`x-3` `:` `x-3, 1` `3x-5` `:` `3x-5, 1` Since `1` is the only common factor, then we can find the LCD.`\text(LCD)` `:` `(x-3)(3x+5)` `(x-3)(3x+5)` -
Question 3 of 6
3. Question
Find the lowest common denominator (LCD) of`(x-2)^2` and `x^2+2x+8`Hint
Help VideoCorrect
Keep Going!
Incorrect
The lowest common denominator (LCD) can also be referred to as the least common multiple (LCM).First, decompose each term into its smallest factors.`(x-2)^2` `=` `(x-2) xx (x-2)` Since the second term is in standard form `(``a``x^2+``b``x+``c``=0)` we can factorise using the cross method.`x^2+``2``x``-8``=0`To factorise, we need to find two numbers that add to `2` and multiply to `-8``4` and `-2` fit both conditions`4 – 2` `=` `2` `4 xx -2` `=` `-8` 
Read across to get the factors.`(x+4)(x-2)=0`Write the factors of the two polynomials next to each other.`(x-2)^2` `=` `(x-2)``(x-2)` `x^2+2x-8` `=` `(x+4)``(x-2)` Combine the red terms and multiply to the black ones.`\text(LCD)` `=` `(x-2)``(x-2)(x+4)` `(x-2)(x-2)(x+4)` -
Question 4 of 6
4. Question
Find the lowest common denominator (LCD) of`x^2-5x+6` and `x^2-x-6`Hint
Help VideoCorrect
Fantastic!
Incorrect
The lowest common denominator (LCD) can also be referred to as the least common multiple (LCM).Since the first polynomial is in standard form `(``a``x^2+``b``x+``c``=0)` we can factorise using the cross method.`x^2``-5``x+``6``=0`To factorise, we need to find two numbers that add to `-5` and multiply to `6``-3` and `-2` fit both conditions`-3 – 2` `=` `-5` `-3 xx -2` `=` `6` 
Read across to get the factors.`(x-3)(x-2)=0`Since the first polynomial is in standard form `(``a``x^2+``b``x+``c``=0)` we can factorise using the cross method.`x^2``-``x``-6``=0`To factorise, we need to find two numbers that add to `-1` and multiply to `-6``-3` and `2` fit both conditions`-3 + 2` `=` `-1` `-3 xx 2` `=` `-6` 
Read across to get the factors.`(x-3)(x+2)=0`Write the factors of the two polynomials next to each other.`x^2-5x+6` `=` `(x-3)``(x-2)` `x^2-x-6` `=` `(x-3)``(x+2)` Combine the red terms and multiply to the black ones.`\text(LCD)` `=` `(x-3)``(x-2)(x+2)` `(x-3)(x-2)(x+2)` -
Question 5 of 6
5. Question
Find the lowest common denominator (LCD) of`x+4` and `x^2+8x+16`Hint
Help VideoCorrect
Excellent!
Incorrect
The lowest common denominator (LCD) can also be referred to as the least common multiple (LCM).Since the second polynomial is in standard form `(``a``x^2+``b``x+``c``=0)` we can factorise using the cross method.`x^2+``8``x+``16``=0`To factorise, we need to find two numbers that add to `8` and multiply to `16``4` and `4` fit both conditions`4 + 4` `=` `8` `4 xx 4` `=` `16` 
Read across to get the factors.`(x+4)(x+4)=0`Write the factors of the two polynomials next to each other and mark similar factors.`x+4` `=` `(x+4)``(1)` `x^2+8x+16` `=` `(x+4)``(x+4)` Combine the red terms and multiply to the black ones.`\text(LCD)` `=` `(x+4)``(x+4)` `(x+4)(x+4)` -
Question 6 of 6
6. Question
Find the lowest common denominator (LCD) of`x`, `x+2` and `x^2-4`Hint
Help VideoCorrect
Nice Job!
Incorrect
The lowest common denominator (LCD) can also be referred to as the least common multiple (LCM).First, decompose each term into its smallest factors.`x` `=` `x xx 1` `x+2` `=` `(x+2) xx 1` `x^2-4` `=` `(x-2)(x+2)` Write the factors of the two polynomials next to each other and mark similar factors.`x` `:` `x,1` `x+2` `:` `(x-2)`,`1` `x^2-4` `:` `(x-2)`,`(x+2)` Combine the red terms and multiply to the black ones.`\text(LCD)` `=` `(x-2)``x(x+2)` `=` `x(x+2)(x-2)` `x(x+2)(x-2)`