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Showing 1 question for Class 8. Tap a card to reveal the answer.
MathematicsAlgebraic Expressions and IdentitiesmediumUse a standard identity to expand (x + 5)^2.
Reveal answer ↓
What it is
Algebraic identities are shortcuts that expand or factor expressions instantly.
Answer
Use the identity (a + b)^2 = a^2 + 2ab + b^2 with a = x and b = 5. So (x + 5)^2 = x^2 + 2(x)(5) + 5^2 = x^2 + 10x + 25.
(a + b)^2 = a^2 + 2ab + b^2
- •(a + b)^2 = a^2 + 2ab + b^2
- •Here a = x, b = 5
- •= x^2 + 10x + 25
Why learn this
They save time in almost every algebra, physics and competitive-exam problem.
💡 Memory trick
Square the first, twice the product, square the last: a^2 + 2ab + b^2.