Question

Expand the (3X-4y)²
using the algebraic identity
x² +y^2-2xy​

Answer 1

Step-by-step explanation:

(3X-4y)²=9X ^ 2+ 16 y^2× 3×4xy

9X ^ 2+ 16 y^2 - 24xy

Answer 2

Answer:

Hello yiren

Using identity (x + a)(x + b) = x2 + (a + b)x + ab

(x + 4)(x + 10) = x2 + (4 + 10)x + 4×10

= x2 + 14x + 40

(ii) (x + 8) (x – 10)

Using identity (x + a)(x + b) = x2 + (a + b)x + ab

(x + 8) (x – 10) = x2 + (8 – 10)x + 8x(-10)

= x2 – 2x – 80x

(iii) (3x + 4) (3x – 5)

Using identity (x + a)(x + b) = x2 + (a + b)x + ab

(3x + 4) (3x – 5) = (3x)2 + (4 – 5)3x + 4x(-5)

= 9x2 – 3x – 20

(iv) (y2+ 3/2 ) (y2– 3/2 )

Using identity (x + a)(x – a) = x2 – a2

(y2+ 3/2 ) (y2– 3/2 ) = y2 – (3/2)2

= y2 – 9/4

(v) (3 – 2x) (3 + 2x)

Using identity (x + a)(x – a) = x2 – a2

(3 – 2x) (3 + 2x)= 32 – (2x)2 = 92 – 4x2