Write down the greatest common factor for each pair of numbers.
(a)GCF of 18 and 30(1)
(b)GCF of 14 and 35(1)
(c)GCF of 24 and 40(1)
2
Factorise each integer by taking out the greatest common factor.
(a)Factorise 28 + 70(1)
(b)Factorise 45 - 15(1)
3
Factorise each algebraic expression by taking out the common factor.
(a)Factorise 6x + 15x(1)
(b)Factorise 4y - 10y(1)
(c)Factorise 9a + 6b(1)
4
Factorise each expression by taking out the highest numeric factor.
(a)Factorise 63p + 21q(1)
(b)Factorise 50m - 20n(1)
5
Factorise each expression fully, taking out common algebraic factors.
(a)Factorise 12x2 + 18x(1)
(b)Factorise 7x - 21x2(1)
(c)Factorise 15y2 - 10y(1)
6
Factorise each expression where one term is negative.
(a)Factorise -6x + 18(1)
(b)Factorise 8 - 12p(1)
7
Factorise each expression completely. Show any common algebraic factors taken out.
(a)Factorise 18x2 - 24x(2)
(b)Factorise 14ab - 21a(2)
8
Factorise each expression where every term has a number and a letter in common.
(a)Factorise 21mn + 14m(1)
(b)Factorise 30xy - 10y(1)
9
Factorise each expression and then check by expanding your answer.
(a)Factorise 16x + 24 and expand your factorised form to check(3)
10
Factorise each expression where the coefficients are small primes.
(a)Factorise 5x + 15(1)
(b)Factorise 11y - 33(1)
11
Apply factorising to simplify an expression used in a context.
(a)A recipe needs 12ab + 6b grams of an ingredient. Factorise to write the amount as a product.(3)
12
Factorise each pair where one term has a squared letter and the other does not.
(a)Factorise x2 + 5x(1)
(b)Factorise 6z2 - 12z(1)
13
Factorise each expression with three terms where a single common factor exists.
(a)Factorise 9x + 3y + 6(2)
(b)Factorise 12a - 8b + 4c(2)
14
Factorise each expression then give the sign of the bracket so that the expression inside is positive where possible.
(a)Factorise -15p + 5 and give factor with positive bracket(3)
15
Solve each equation by factorising. Show your steps.
(a)Solve 6x - 18 = 0(4)
16
Factorise each expression that includes a decimal coefficient.
(a)Factorise 0.6x + 1.8(1)
(b)Factorise 2.5y - 7.5(1)
17
A school buys 18 identical packs and 24 identical rulers. The total cost is 18p + 24r. Factorise the total cost to show the cost of one set containing a pack and a ruler.
(a)Write the total cost 18p + 24r as a product showing the cost of one pack and one ruler.(3)
18
Stretch: Factorise fully and then indicate whether the bracket contains only positive terms. Explain how you know.
(a)Factorise -12k + 8 - 16k and say whether the bracket has only positive terms.(3)
Mark scheme · KS3.M-A9 Factorising into Single Brackets
Question 1
(a) B1 6 cao
(a) Answer: 6
(b) B1 7 cao
(b) Answer: 7
(c) B1 8 cao
(c) Answer: 8
Question 2
(a) B1 2(14 + 35) or 14(2 + 5) oe
(a) Answer: 14(2 + 5)
(b) B1 15(3 - 1) oe
(b) Answer: 15(3 - 1)
Question 3
(a) B1 3x(2 + 5) or 3x(7) not required but factor form 3x(2+5) oe
(a) Answer: 3x(2 + 5)
(b) B1 2y(2 - 5) oe
(b) Answer: 2y(2 - 5)
(c) B1 3(3a + 2b) oe
(c) Answer: 3(3a + 2b)
Question 4
(a) B1 21(3p + q) cao
(a) Answer: 21(3p + q)
(b) B1 10(5m - 2n) cao
(b) Answer: 10(5m - 2n)
Question 5
(a) B1 6x(2x + 3) cao
(a) Answer: 6x(2x + 3)
(b) B1 7x(1 - 3x) oe
(b) Answer: 7x(1 - 3x)
(c) B1 5y(3y - 2) cao
(c) Answer: 5y(3y - 2)
Question 6
(a) B1 -6(x - 3) or 6( -x + 3) oe
(a) Answer: -6(x - 3)
(b) B1 4(2 - 3p) cao
(b) Answer: 4(2 - 3p)
Question 7
(a) M1 method: factor common number and x, e.g. 6x taken out
(a) A1 6x(3x - 4) cao
(a) Answer: 6x(3x - 4)
(b) M1 method: take out 7a
(b) A1 7a(2b - 3) cao
(b) Answer: 7a(2b - 3)
Question 8
(a) B1 7m(3n + 2) cao
(a) Answer: 7m(3n + 2)
(b) B1 10y(3x - 1) cao
(b) Answer: 10y(3x - 1)
Question 9
(a) M1 factor method, take out 8
(a) M1 correct factorised form 8(2x + 3)
(a) A1 expansion 16x + 24 cao
(a) Answer: 8(2x + 3)
Question 10
(a) B1 5(x + 3) cao
(a) Answer: 5(x + 3)
(b) B1 11(y - 3) cao
(b) Answer: 11(y - 3)
Question 11
(a) M1 identify common factor 6b
(a) M1 write factorised form 6b(2a + 1)
(a) A1 final answer 6b(2a + 1) cao
(a) Answer: 6b(2a + 1)
Question 12
(a) B1 x(x + 5) cao
(a) Answer: x(x + 5)
(b) B1 6z(z - 2) cao
(b) Answer: 6z(z - 2)
Question 13
(a) M1 identify GCF 3
(a) A1 3(3x + y + 2) cao
(a) Answer: 3(3x + y + 2)
(b) M1 identify GCF 4
(b) A1 4(3a - 2b + c) cao
(b) Answer: 4(3a - 2b + c)
Question 14
(a) M1 take out -5 or 5 and change signs correctly
(a) M1 write factor form -5(3p - 1) or 5( -3p + 1) method
(a) A1 -5(3p - 1) cao
(a) Answer: -5(3p - 1)
Question 15
(a) M1 factor out 6 to give 6(x - 3) = 0
(a) M1 use zero product principle or divide both sides by 6
(a) M1 isolate x showing x - 3 = 0
(a) A1 x = 3 cao
(a) Answer: 3
Question 16
(a) B1 0.6(x + 3) oe
(a) Answer: 0.6(x + 3)
(b) B1 2.5(y - 3) cao
(b) Answer: 2.5(y - 3)
Question 17
(a) M1 identify common factor 6
(a) M1 write 6(3p + 4r)
(a) A1 6(3p + 4r) cao
(a) Answer: 6(3p + 4r)
Question 18
(a) M1 correct factor taken out, e.g. -4
(a) M1 correct factorised form -4(3k - 2 + 4k) or simplified -4(7k - 2)
(a) A1 state that the bracket 7k - 2 is not all positive for small k and explain oe