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Question
Factorise the following:
`x^2 + (11x)/6 - 5/3`
Sum
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Solution
Given: `x^2 + (11x)/6 - 5/3`
Step-wise calculation:
Step 1: Remove fractions by multiplying entire expression by 6
`6(x^2 + (11x)/6 - 5/3)`
Distribute:
6x2 + 11x – 10
Now we factorise:
6x2 + 11x – 10
Step 2: Split the middle term
We need two numbers whose:
Product = 6 × (–10) = –60
Sum = 11
The numbers are 15 and –4
Because 15 + (–4) = 11, 15 × (–4) = –60
Step 3: Rewrite and factor by grouping
6x2 + 15x – 4x – 10
Group:
(6x2 + 15x) – (4x + 10)
Factor each group:
3x(2x + 5) – 2(2x + 5)
Now take out the common bracket:
(2x + 5)(3x – 2)
Thus:
6x2 + 11x – 10 = (2x + 5)(3x – 2)
Step 4: Put back the factor 6
We had multiplied by 6 earlier, so divide by 6:
`x^2 + (11x)/6 - 5/3 = 1/6(2x + 5)(3x - 2)`
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