Factorise algebraic expressions in this structured online self marking exercise.
This is level 6: factorising an expression which is the difference between two squares. You can earn a trophy if you get at least 9 questions correct and you do this activity online.
Factorise the following expressions. Type the bracket containing the plus sign before the bracket containing the minus sign.
Try your best to answer the questions above. Type your answers into the boxes provided leaving no spaces. As you work through the exercise regularly click the "check" button. If you have any wrong answers, do your best to do corrections but if there is anything you don't understand, please ask your teacher for help.
When you have got all of the questions correct you may want to print out this page and paste it into your exercise book. If you keep your work in an ePortfolio you could take a screen shot of your answers and paste that into your Maths file.
This web site contains over a thousand free mathematical activities for teachers and pupils. Click here to go to the main page which links to all of the resources available.
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Mathematicians are not the people who find Maths easy; they are the people who enjoy how mystifying, puzzling and hard it is. Are you a mathematician?
Comment recorded on the 23 September 'Starter of the Day' page by Judy, Chatsmore CHS:
"This triangle starter is excellent. I have used it with all of my ks3 and ks4 classes and they are all totally focused when counting the triangles."
Comment recorded on the 9 April 'Starter of the Day' page by Jan, South Canterbury:
"Thank you for sharing such a great resource. I was about to try and get together a bank of starters but time is always required elsewhere, so thank you."
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Learning and understanding Mathematics, at every level, requires learner engagement. Mathematics is not a spectator sport. Sometimes traditional teaching fails to actively involve students. One way to address the problem is through the use of interactive activities and this web site provides many of those. The Go Maths page is an alphabetical list of free activities designed for students in Secondary/High school.
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Level 1 - Factorising an expression with a constant factor.
Example: 40h + 88
Level 2 - Factorising an expression with a variable factor.
Example: 23h + 3h²
Level 3 - Factorising an expression with both a constant and variable factor.
Example: 10a + 2ab
Level 4 - Writing an expression of two parts that can be separately factorised.
Example: 3a + ab + 5w + 4wy
Level 5 - Writing an expression as the product of two binomials.
Example: 5a + 5b + ac + bc
Level 6 - Factorising an expression which is the difference between two squares.
Example: c² - 81
Level 7 - Factorising a quadratic where the squared term coefficient is 1.
Example: c² - 13c + 36
Level 8 - Factorising a quadratic where the squared term coefficient is not 1.
Example: 4a² + 5a - 6
Level 9 - Mixed factorisation questions
Example: b² + 6b + 9
Projectable large format factorising quadratics exercise suitable for whole class use.
This program checks your answers by matching the text you have typed in with the options it has as the correct answer. For that reason it does not always recognise equivalent correct answers. For example the factorisation of 6a+21 can be written as 3(2a+7) or 3(7+2a) but the program may only recognise the first option as the correct answer. Please type in your answers so that the terms are in alphabetical order of the variables followed by the constants unless a negative cooeficient of the viariable makes the opposite a more elegant solution.
Identify a common factor of 8 to give \(8(5h+11)\)
Identify a common factor of h to give \(h(23+3h)\)
Identify a common factor of 2a to give \(2a(5+b)\)
Identify common factors of pairs of terms to give \(a(3+b)+w(5+4y)\)
Extract common factors of pairs of terms to give \(5(a+b) + c(a+b)\)
Then extract a common factor of (a+b) to give \((a+b)(5+c)\)
This can be written as \( (c+9)(c-9) \). Expand the brackets to see why
Start by finding two numbers with a product of 36 and sum of -13
These numbers are -4 and -9
So the factorisation is \( (c-4)(c-9) \)
Multiply the coefficient of a² by the constant term: \( 4 \times -6 = -24 \)
Now find two numbers with a product of -24 and sum of 5 (the coefficient of a)
These numbers are -3 and 8
Write the original expression with the middle term split into these two numbers: \( 4a^2-3a+8a-6\)
Extract common factors of pairs of terms to give \( a(4a-3) + 2(4a-3)\)
Then extract a common factor of (4a-3) to give \((a+2)(4a-3)\)
Use the techniques used in the previous levels
Don't wait until you have finished the exercise before you click on the 'Check' button. Click it often as you work through the questions to see if you are answering them correctly. You can double-click the 'Check' button to make it float at the bottom of your screen.