Question

Answer it :-

Solve using identity

(3x + 4 + 2)^2 = ?
(2x + 9)^2 = ?
(81)^2 = ?
(2x + 5)(2x - 5) = ?

Answer 1

❣ (3x + 4 + 2)^2
using ➡ (a+b+c)^2 = a^2+b^2+c^2+2ab+2bc+2ca

➡ (3x)^2+(4)^2+(2)^2+2(3x)(4)+2(4)(2)+2(2)(3x)
➡ 9x^2 + 16 + 4 + 24x + 16 + 12x
➡ 9x^2 + 36 + 36x

❣ (2x + 9)^2
using (a + b)^2 = a^2 + b^2 + 2ab

➡ (2x)^2 + (9)^2 + 2(2x)(9)
➡ 4x^2 + 81 + 36x

❣ (81)^2 = (80 + 1)^2
using (a + b)^2 = a^2 + b^2 + 2ab

➡ (80)^2 + (1)^2 + 2(80)(1)
➡ 6400 + 1 + 160
➡ 6561

❣ (2x + 5)(2x - 5)
using (a + b)(a - b) = a^2 - b^2

➡ (2x)^2 - (5)^2
➡ 4x^2 - 25

Answer 2

4 .(2x + 5)(2x-5)

(2x)(2x)+(2x)(-5)+(5)(2x)+(5)(-5)

4x^ -10x + 10x - 25

4x^ + 0 - 25

4x^- 25

3. (81)^2 = 6561