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2. Example Questions 1 Ex Q1. 7y + 6 (a) y = 3 (b) y = 0 (c) y = -3 (a) = 7 x 3 + 6 = 21 + 6 = 27 (b) = 7 x 0 + 6 = 0 + 6 = 6 (c) = 7 x (-3) + 6 = -21 + 6 = -15 (a) = 8 - 3 x 1 = 8 - 3 = 5 (b) = 8 - 3 x 7 = 8 - 21 = -13 (c) = 8 - 3(-4) = 8 + 12 = 20 + x + = + + x - = - - x + = - - x - = + Replacing the variables in an expression with numbers is called substitution. We need to be able to substitute both positive and negative numbers within expressions that contain one or more variables. Substitution 8 - 3p (a) p = 1 (b) p = 7 (c) p = -4 Ex Q2. We will evaluate each of the expressions below for the given values. BODMAS

3. Questions 1 Questions + x + = + + x - = - - x + = - - x - = + Evaluate the following expressions for each given variable. 31 42 -3 -16 15 -4 -40 1. 4k + 3 (k = 7) 2. 9p + 15 (p = 3) 3. 5 x - 3 ( x = 0) 4. 7 x - 30 ( x = 2) 5. 9 - 2z (z = -3) 6. 8 - 6k (k = 2) 7. -6q + 2 (q = 7 ) 8. 8r - 7 (r = - ¼ ) -9 Substitution

4. Example Questions 2 Ex Q3. q 2 + 3 (a) q = 4 (b) q = 0 (c) q = -5 (a) = 4 2 + 3 = 16 + 3 = 19 (b) = 0 2 + 3 = 0 + 3 = 3 (c) = (-5) 2 + 3 = 25 + 3 = 28 (a) = 2 x 3 2 - 20 = 18 - 20 = - 2 (b) = 2 x 6 2 - 20 = 72 - 20 = 52 (c) = 2 x (-4) 2 -20 = 32 - 20 = 12 + x + = + + x - = - - x + = - - x - = + Replacing the variables in an expression with numbers is called substitution. We need to be able to substitute both positive and negative numbers within expressions that contain one or more variables. Substitution 2m 2 - 20 (a) m = 3 (b) m = 6 (c) m = -4 Ex Q4. We will evaluate each of the expressions below for the given values. BODMAS

5. Questions 2 Questions + x + = + + x - = - - x + = - - x - = + Evaluate the following expressions for each given variable. 21 20 42 55 -9 -5 34 1. 2k 2 + 3 (k = 3) 2. p 3 + 12 (p = 2) 3. 5 x 2 - 3 ( x = 3) 4. x 2 + 30 ( x = -5) 5.9 - 2z 2 (z = -3) 6. 4k 3 - 9 (k = 1) 7. 8q 2 + 2 (q = -2 ) 8. 8r 2 - 7 (r = - ½ ) -5 Substitution

6. Example Questions 3 Ex Q5. 3a + b (a) a = 2, b =3 (b) a = -4, b = 1 (a) = 3 x 2 + 3 = 6 + 3 = 9 (b) = 3 x (-4) + 1 = -12 + 1 = -11 (a) = 4 x 2 - 5 = 8 - 5 = 3 (b) = - 2 x 3 + 2 = -6 + 2 = -4 + x + = + + x - = - - x + = - - x - = + Replacing the variables in an expression with numbers is called substitution. We need to be able to substitute both positive and negative numbers within expressions that contain one or more variables. Substitution pq - v (a) p = 4, q = 2, v = 5 (b) p = -2, q = 3, v = -2 Ex Q6. We will evaluate each of the expressions below for the given values. BODMAS

7. Example Questions 4 Ex Q7. 3e + 2f (a) e = 6, f = 2 (b) e = -3, f = -1 (a) = 3 x 6 + 2 x 2 = 18 + 4 = 22 (b) = 3 x (-3) + 2 x (-1) = -9 - 2 = -11 (a) = 2 x 1 x 2 - 3 x (-3 ) = 4 + 9 = 13 (b) = 2 x (-3) x (-2) - 3 x (-5) = 12 + 15 = 27 + x + = + + x - = - - x + = - - x - = + Replacing the variables in an expression with numbers is called substitution. We need to be able to substitute both positive and negative numbers within expressions that contain one or more variables. Substitution 2mn - 3q (a) m = 1, n = 2, q = -3 (b) m = -3, n = -2, q = -5 Ex Q8. We will evaluate each of the expressions below for the given values. BODMAS

8. Questions 3 + x + = + + x - = - - x + = - - x - = + Evaluate the following expressions for each given variable. 204. 2ab + c (a = 3, b = 2, c = 8) Substitution 5. 3pq + v (p = 2, q = 5, v = -4) BODMAS 26 6. 5st + 3v (s = -4, t = 2, v = 6) -22 1. 2a + b (a = 3, b = 9) 2. 3p - q (p = 2, q = 8,) 3. 5s + 2t (s = -4, t = -2,) 15 -2 -24 7. 2pqr - v (p = -3, q = -2, r = 4, v = -3) 51

9. Worksheet worksheet 4. 2ab + c (a = 3, b = 2, c = 8) 5. 3pq + v (p = 2, q = 5, v = -4) 6. 5st + 3v (s = -4, t = 2, v = 6) 1. 2a + b (a = 3, b = 9) 2. 3p - q (p = 2, q = 8,) 3. 5s + 2t (s = -4, t = -2,) 7. 2pqr - v (p = -3, q = -2, r = 4, v = -3) 1. 4k + 3 (k = 7) 2. 9p + 15 (p = 3) 3. 5 x - 3 ( x = 0) 4. 7 x - 30 ( x = 2) 5. 9 - 2z (z = -3) 6. 8 - 6k (k = 2) 7. -6q + 2 (q = 7 ) 8. 8r - 7 (r = - ¼ ) 1. 2k 2 + 3 (k = 3) 2. p 3 + 12 (p = 2) 3. 5 x 2 - 3 ( x = 3) 4. x 2 + 30 ( x = -5) 5.9 - 2z 2 (z = -3) 6. 4k 3 - 9 (k = 1) 7. 8q 2 + 2 (q = -2 ) 8. 8r 2 - 7 (r = - ½ ) Questions 1Questions 2Questions 3