SPM 2020 Add Maths Paper 1, Question 7Indices, Surds & Logarithms

Solved on video in English and Bahasa Melayu · 4 marks · Form 4, Indices, Surds & Logarithms · 4:27 video

The question

(a)

Given p = a², q = a⁴ * b and r = 2ab, express (32pq)/r² in terms of a and/or b.

[2 marks]

(b)

Given log_9 [ log_x (2y - 5) ] = 1/2, express y in terms of x.

[2 marks]

Step 1

Substitute: (32pq)/r² = (32 * a² * a⁴ * b)/(2ab)².

4 more steps, each with the reason for it, in the full solution

Final answer

8a⁴/b

Where students lose marks

Watch out: r² means (2ab)² = 4a²b², so square the 2 as well. Using r² = 2ab gives a wrong answer like 16a⁵.

3 more steps, each with the reason for it, in the full solution

Final answer

y = (x³ + 5)/2

Where students lose marks

Watch out: log_x(2y − 5) cannot become log_x(2y/5). There is no subtraction law, so use the definition: 2y − 5 = x³.

Watch every step of this question solved on video (4:27), with the reason behind each step and a box that checks your own answer.

No card. Every past-year question on video, in English and BM.

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