Question

. Write expand :
a) (ab+bc) ²
b) (2x - 3y + 4)²
c) (3x-5y)³​

Answer 1

Step-by-step explanation:

Given, (ab+bc)2−2ab2c.

We know,

(a+b)2=a2+2ab+b2.

Then,

(ab+bc)2−2ab2c

=(ab)2+2(ab)(bc)+(bc)2−2ab2c

=a2b2+2ab2c+b2c2−2ab2c

=a2b2+b2c2.

2−3+4)(2−3+4)

2(2−3+4)−3(2−3+4)+4(2−3+4

Using the identity is (a+b)(a−b)=a2−b2.

Given: (3x−5y)(3x+5y) we apply the above identity by taking 

a=3x and b=5y 

We get, (3x−5y)(3x+5y)=(3x)2−(5y)2=9x2−25y2

Hence, (3x−5y)(3x+5y)=9x2−25y2.