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0580/32 Oct/Nov 2021, Question 5: Simultaneous Equations by Elimination

Cambridge IGCSE Mathematics 0580 · Paper 32 (Core) · Calculator · 12 marks

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The question, in short

Answer five algebra items: simplify an expression, evaluate 8x − 3y, solve a linear equation, rearrange P = 6t − 11 for t, and solve two simultaneous equations showing working.

Summarised in our own words. Use the official paper for the exact wording and any diagrams.

Part (a) · 2 marks

Simplify 5a − 3b + 7a + 2b by collecting like terms.

  1. 15a + 7a = 12a and −3b + 2b = −b
  2. 2= 12a − b

Answer12a − b

Part (b) · 2 marks

Work out 8x − 3y given x = 5 and y = −2.

  1. 18 × 5 − 3 × (−2) = 40 + 6
  2. 2= 46

Answer46

Part (c) · 2 marks

Solve 6x − 3 = 2x + 8 for x.

  1. 16x − 2x = 8 + 3
  2. 24x = 11
  3. 3x = 2.75

Answer2.75 or 2 3/4

Part (d) · 2 marks

Rearrange P = 6t − 11 to make t the subject.

  1. 1P + 11 = 6t
  2. 2t = (P + 11)/6

Answer(P + 11)/6

Part (e) · 4 marks

Solve 3x − 4y = 30 and 2x + 5y = −3 simultaneously, showing all working.

  1. 1×2: 6x − 8y = 60; ×3: 6x + 15y = −9
  2. 2Subtract: −23y = 69, y = −3
  3. 33x − 4(−3) = 30, 3x = 18
  4. 4x = 6, y = −3

Answerx = 6, y = −3

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Also searched as: 0580/32/O/N/21 · 0580_w21_qp_32 · 0580 w21 32 · question 5.
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