Mixed Topic Worksheet Grades 8/9: Day 063
- 1
Question 1. On a histogram the bar for 20 < x ≤ 30 has frequency density 4.8 and the bar for 30 < x ≤ 50 has frequency density 3. Elsa says the class 20 < x ≤ 30 has more values. Is she correct? Show your working.
Interpreting Histograms▶ Show worked answerHide worked answer
- M1: 4.8×10=48 and 3×20=60
- B1: No
- B1: the class 30 < x ≤ 50 has more (60 against 48)
Answer: No: 20 < x ≤ 30 has 48 values, 30 < x ≤ 50 has 60[3 marks] - 2
Question 2. By completing the square, solve x² + 4x - 1 = 0. Give your answers in surd form.
Solving Quadratics by Completing the Square (a = 1)▶ Show worked answerHide worked answer
- M1: (x + 2)² - 5 = 0
- M1 A1: x = -2 ± √5
Answer: x = -2 + √5 or x = -2 - √5[3 marks] - 3
Question 3. PA and PB are tangents to a circle with centre O, touching it at A and B. C is a point on the major arc AB. Angle OAB = 28°. Work out the size of angle ACB. Give reasons.
Combining Circle Theorems▶ Show worked answerHide worked answer
- M1: OA = OB so angle OBA = 28° and angle AOB = 180 - 2 × 28
- M1: angle ACB = AOB ÷ 2 = 124 ÷ 2
- A1: 62°
Answer: 62°[3 marks] - 4
Question 4. Simplify fully dfracx²+7x+10x²-1÷dfracx+5x-1
Multiplying & Dividing Algebraic Fractions▶ Show worked answerHide worked answer
- M1: dfracx²+7x+10x²-1×dfracx-1x+5
- M2: (x+2)(x+5) and (x-1)(x+1), cancels (x+5) and (x-1)
- A1: dfracx+2x+1
Answer: dfracx+2x+1[4 marks] - 5
Question 5. Beth rationalises dfrac32 + √5 and gets dfrac32 + √5 × dfrac2 - √52 - √5 = dfrac6 - 3√54 + 5 = dfrac2 - √53 This is wrong. Work out the correct answer.
Rationalising Denominators of the Form a ± √b▶ Show worked answerHide worked answer
- M1: 4 - 5 = -1
- A1: dfrac6 - 3√5-1 = 3√5 - 6
Answer: 3√5 - 6[2 marks]
Mixed Topic Worksheet Grades 8/9: Day 063
- 1
Question 1. On a histogram the bar for 20 < x ≤ 30 has frequency density 4.8 and the bar for 30 < x ≤ 50 has frequency density 3. Elsa says the class 20 < x ≤ 30 has more values. Is she correct? Show your working.
[3 marks]Interpreting Histograms▶ Show worked answerHide worked answer
- M1: 4.8×10=48 and 3×20=60
- B1: No
- B1: the class 30 < x ≤ 50 has more (60 against 48)
Answer: No: 20 < x ≤ 30 has 48 values, 30 < x ≤ 50 has 60 - 2
Question 2. By completing the square, solve x² + 4x - 1 = 0. Give your answers in surd form.
[3 marks]Solving Quadratics by Completing the Square (a = 1)▶ Show worked answerHide worked answer
- M1: (x + 2)² - 5 = 0
- M1 A1: x = -2 ± √5
Answer: x = -2 + √5 or x = -2 - √5 - 3
Question 3. PA and PB are tangents to a circle with centre O, touching it at A and B. C is a point on the major arc AB. Angle OAB = 28°. Work out the size of angle ACB. Give reasons.
[3 marks]Combining Circle Theorems▶ Show worked answerHide worked answer
- M1: OA = OB so angle OBA = 28° and angle AOB = 180 - 2 × 28
- M1: angle ACB = AOB ÷ 2 = 124 ÷ 2
- A1: 62°
Answer: 62° - 4
Question 4. Simplify fully dfracx²+7x+10x²-1÷dfracx+5x-1
[4 marks]Multiplying & Dividing Algebraic Fractions▶ Show worked answerHide worked answer
- M1: dfracx²+7x+10x²-1×dfracx-1x+5
- M2: (x+2)(x+5) and (x-1)(x+1), cancels (x+5) and (x-1)
- A1: dfracx+2x+1
Answer: dfracx+2x+1 - 5
Question 5. Beth rationalises dfrac32 + √5 and gets dfrac32 + √5 × dfrac2 - √52 - √5 = dfrac6 - 3√54 + 5 = dfrac2 - √53 This is wrong. Work out the correct answer.
[2 marks]Rationalising Denominators of the Form a ± √b▶ Show worked answerHide worked answer
- M1: 4 - 5 = -1
- A1: dfrac6 - 3√5-1 = 3√5 - 6
Answer: 3√5 - 6
Mixed Topic Worksheet Grades 8/9: Day 063
- 1
Question 1. On a histogram the bar for 20 < x ≤ 30 has frequency density 4.8 and the bar for 30 < x ≤ 50 has frequency density 3. Elsa says the class 20 < x ≤ 30 has more values. Is she correct? Show your working.
Interpreting Histograms▶ Show worked answerHide worked answer
- M1: 4.8×10=48 and 3×20=60
- B1: No
- B1: the class 30 < x ≤ 50 has more (60 against 48)
Answer: No: 20 < x ≤ 30 has 48 values, 30 < x ≤ 50 has 60[3 marks] - 2
Question 2. By completing the square, solve x² + 4x - 1 = 0. Give your answers in surd form.
Solving Quadratics by Completing the Square (a = 1)▶ Show worked answerHide worked answer
- M1: (x + 2)² - 5 = 0
- M1 A1: x = -2 ± √5
Answer: x = -2 + √5 or x = -2 - √5[3 marks] - 3
Question 3. PA and PB are tangents to a circle with centre O, touching it at A and B. C is a point on the major arc AB. Angle OAB = 28°. Work out the size of angle ACB. Give reasons.
Combining Circle Theorems▶ Show worked answerHide worked answer
- M1: OA = OB so angle OBA = 28° and angle AOB = 180 - 2 × 28
- M1: angle ACB = AOB ÷ 2 = 124 ÷ 2
- A1: 62°
Answer: 62°[3 marks] - 4
Question 4. Simplify fully dfracx²+7x+10x²-1÷dfracx+5x-1
Multiplying & Dividing Algebraic Fractions▶ Show worked answerHide worked answer
- M1: dfracx²+7x+10x²-1×dfracx-1x+5
- M2: (x+2)(x+5) and (x-1)(x+1), cancels (x+5) and (x-1)
- A1: dfracx+2x+1
Answer: dfracx+2x+1[4 marks] - 5
Question 5. Beth rationalises dfrac32 + √5 and gets dfrac32 + √5 × dfrac2 - √52 - √5 = dfrac6 - 3√54 + 5 = dfrac2 - √53 This is wrong. Work out the correct answer.
Rationalising Denominators of the Form a ± √b▶ Show worked answerHide worked answer
- M1: 4 - 5 = -1
- A1: dfrac6 - 3√5-1 = 3√5 - 6
Answer: 3√5 - 6[2 marks]