(2a+b)square-9

Question

factorise

Answer 1

A² - B² = (A - B)(A + B)

 

(2a+b)² - 3² = (2a+b - 3)(2a+b + 3)

Answer 2

(2a+b)² - 9 is the difference between 2 squares -- the square of 2a+b and the square of 3.  The factors of the difference between 2 squares are:  the sum of the two numbers being squared, and the difference between the two numbers being squared.

 

In this case you would get:

 

(2a + b + 3)(2a + b - 3)

 

 

Answer 3

(2a + b)^{2 _{=  9}}

2a + b = 3, 2a + b = -3

(2a +b -3)(2a +b +3)