plz try to this question as soon as possible urgent correct answer plz try to answer maximus 3 or 2 questions plz plz
Answers
1. Add 11x² - 8x + 4 and 6x² + 7x - 10
⇒ (11x² - 8x + 4) + (6x² + 7x - 10)
⇒ 11x² - 8x + 4 + 6x² + 7x - 10
Combine Like Terms.
⇒ (11x² + 6x²) + (7x - 8x) + (4 - 10)
Simplify.
⇒ 17x² - 1x - 6
⇒ 17x² - x - 6
∴ When we add 11x² - 8x + 4 and 6x² + 7x - 10 we get 17x² - x - 6.
_______________________________
2. Simplify -: (a + b)² - 4ab
Apply the identity (a+b)² = a² + 2ab + b² to simplify.
⇒ (a + b)² - 4ab
⇒ a² + 2ab + b² - 4ab
Combine like terms.
⇒ a² + b² + (2ab - 4ab)
Simplify.
⇒ a² + b² + (-2ab)
⇒ a² + b² - 2ab
Rearrange.
⇒ a² - 2ab + b²
⇒ (a - b)²
∴ (a + b)² - 4ab = a² - 2ab + b² (or) (a - b)²
_______________________________
3. Using suitable identity find: 102 × 105
⇒ 102 × 105
⇒ (100 + 2) × (100 + 5)
Apply the identity -: (x + a)(x + b) = x² + (a + b)x + ab.
Here,
x = 100
a = 2
b = 5
⇒ (100)² + (2 + 5) × 100 + (2 × 5)
Simplify.
⇒ 10000 + (7 × 100) + 10
⇒ 10000 + 700 + 10
⇒ 10710
∴ 102 × 105 = 10710
_______________________________
4. Divide x² - 10x + 21 by (x - 7)
(Answer attached)
_______________________________
