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Find the discriminant of .

Class 10Quadratic EquationsAlgebra — Quadratics
  • A73
  • B25
  • C−25
  • D5

Step-by-Step Solution

. Since and 25 is a perfect square, the roots are rational and distinct. 73 comes from 49 + 24 (adding instead of subtracting); −25 comes from computing 24 − 49; and 5 is , which appears inside the formula but is not the discriminant itself.
Answer: B) 25

Key idea: Method 1: Factorisation

Rewrite as a product , then use the **zero-product property**: a product is zero iff one of its factors is zero.

**Steps for :
1. Find two numbers that MULTIPLY to and ADD to .
2. Use them as the constants in .

**Example**: → product 12, sum −7 → numbers −3 and −4 → → or 4.

**For with a ≠ 1**: split the middle term — find two numbers multiplying to and summing to . Then group.

Example: , sum = 7 → 6 and 1. Split: → or −3.

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