If roots of x² - 7x + 10 = 0 are multiplied by 3, new equation is?
- x² - 21x + 90 = 0
- x² - 23x + 90 = 0
- x² - 25x + 90 = 0
- None of these
Explanation
Given: x² - 7x + 10 = 0
Step 1: Find original roots
x² - 7x + 10 = (x - 2)(x - 5) = 0
So roots are 2 and 5
Step 2: Multiply roots by 3
New roots = 2 × 3 = 6, 5 × 3 = 15
Step 3: Form new equation
If roots are α and β, equation is x² - (α+β)x + αβ = 0
Here α+β = 6 + 15 = 21
αβ = 6 × 15 = 90
Therefore new equation = x² - 21x + 90 = 0
Last verified on 15-05-2026
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