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4MA1/1F Jun 2025, Question 21: Index Laws with Letters

Pearson Edexcel International GCSE Mathematics A 4MA1 · Paper 1F (Foundation) · Calculator · 4 marks

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The question, in short

Apply index laws to find m in x⁵ × x⁷ = xᵐ, find n in y⁸ ÷ y³ = yⁿ, and simplify (5a⁴r²)³ fully.

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Part (a) · 1 mark

Find the value of m from x⁵ × x⁷ = xᵐ.

  1. 1x⁵ × x⁷ = x⁵⁺⁷
  2. 2= x¹²
  3. 3m = 12

Answer12

Part (b) · 1 mark

Find the value of n from y⁸ ÷ y³ = yⁿ.

  1. 1y⁸ ÷ y³ = y⁸⁻³
  2. 2= y⁵
  3. 3n = 5

Answer5

Part (c) · 2 marks

Simplify fully the expression (5a⁴r²)³.

  1. 15³ = 125
  2. 2(a⁴)³ = a¹²
  3. 3(r²)³ = r⁶
  4. 4125a¹²r⁶

Answer125a¹²r⁶

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