Starter Multiply the following 2a x 3b 3s x 4t 4d x 6d 3a x a x b 5y x 4z x y

Expanding brackets Learning Objectives: Key Words To be able to expand brackets in algebra. Key Words Expanding Expression Algebra brackets

L.O : To be able expand brackets in algebra. +4

L.O : To be able expand brackets in algebra. +3

L.O : To be able expand brackets in algebra.

L.O : To be able expand brackets in algebra. 3(2d-3e) 3 (2d-3e) = 6d -9e

L.O : To be able expand brackets in algebra. 7a(2b-3c) 7a (2b-3c) = 14ab -21ac

L.O : To be able expand brackets in algebra. Expand the following brackets 4(2a+4) 5(3b-c) 3(4b-2c) 6(3h-4k) 8( 3r-2q-s) Answer 8a+16 15b-5c 12b-6c 18h-24k 24r-16q-8s

Expanding brackets and simplifying Expand and simplify: 2(3n – 4) + 3(3n + 5) We need to multiply out both brackets and collect together like terms. 2(3n – 4) + 3(3n + 5) = 6n – 8 + 9n + 15 In this example, we have two sets of brackets. The first set is multiplied by 2 and the second set is multiplied by 3. We don’t need to use a grid as long as we remember to multiply every term inside the bracket by every term outside it. Talk through the multiplication of (3n – 4) by 2 and (3n + 5) by 3. Let’s write the like terms next to each other. When we collect the like terms together we have 6n + 9n which is 15n and –8 + 15 = 7. = 6n + 9n – 8 + 15 = 15n + 7

Merit Question 5 Minutes Expand and simplify: 5(3a + 2b) – a(2 + 5b) We need to multiply out both brackets and collect together like terms. 5(3a + 2b) – a(2 + 5b) = 15a + 10b – 2a – 5ab Here is another example with two sets of brackets. The first set is multiplied by 5 and the second set is multiplied by minus a. Talk through the multiplication of (3a + 2b) by 5. Next we need to multiply (2 + 5b) by –a. Talk through this. = 15a – 2a + 10b – 5ab NB: (negative × positive = negative) -a × 5b = -5ab = 13a + 10b – 5ab