Grade DE Substitution Substitute numerical values into formulae

Grade D/E Substitution Substitute numerical values into formulae and expressions, including scientific formulae If you have any questions regarding these resources or come across any errors, please contact helpful-report@pixl. org. uk

Key Vocabulary Substitute Formulae Scientific formulae Value Numerical Expression

How to substitute into a formula If x = 7 and we have the expression x + 5 then: - 7 + 5 = 12

How to substitute into a formula If x = 10 and we have the expression 2 x + 5 then: - 20 + 5 = 25 2 x 10

How to substitute into a formula If x = 9 and we have the expression 2(x – 3) then: - 2( 9 - 3) = 2 x 6 = 12

How to substitute into a formula If x = 15 and we have the expression √(x + 1) then: - √(15 + 1) = √ 16 = 4

How to substitute into a formula If a = 10 and we have the expression 3 a 2 then: - 3 x 2 10 = 3 x 100 = 300

How to substitute into a formula If a = -4 and we have the expression 3 a then: - 3 x - 4 = - 12

Substitute - now you try. . . If a = 5 and b = 6 evaluate: 1) a + b 4) b - a 2) ab 5) 4 b 3) 3 a 6) 3 ab

Substitute - now you try. . . If a = 5 and b = 6 evaluate: 1) a + b =11 4) b - a =1 2) ab =30 5) 4 b =24 3) 3 a =15 6) 3 ab =90

Substitute - now you try. . .

Substitute - now you try. . . =12 =16 =80 =26 =14 =3

Substitute into scientific formulae Find the value of v when u = 22. 5, a = 3, t = 5 v = u + at Find the value of V when r = 3. Answer in terms of π. V=

Substitute into scientific formulae Find the value of v when u = 22. 5, a = 3, t = 5 v = u + at v = 22. 5 + (3 x 5) = 22. 5 + 15 = 37. 5 Find the value of V when r = 3. Answer in terms of π. V= V = 4/3 x π x 27 = 36π

Problem Solving and Reasoning Substitute – explain the mistakes 1) 3 p = 36 2) p + q = 8 3) p - q = 4 4) 2 p 2 = 144 5) 4 q² = -16 p=6 q = -2

Problem Solving and Reasoning Substitute – explain the mistakes 1) 3 p = 36 18 2) p + q = 8 4 3) p - q = 4 8 4) 2 p 2 = 144 72 5) 4 q² = -16 16 p=6 q = -2

Problem Solving and Reasoning x+ 7 3 x Show the perimeter of the rectangle is 8 x + 14 Calculate the perimeter when x = 4

Problem Solving and Reasoning x+ 7 3 x Show the perimeter of the rectangle is 8 x + 14 Calculate the perimeter when x = 4 Perimeter = 46