Question

4. Simplify: (3x+5y)² +(3x-5y)²​

Answer 1

Answer:

18xsquare + 50ysquare is the answer

Answer 2

Answer:   18 x² + 50 y²

Step-by-step explanation:

(3x+5y)² +(3x-5y)²​

Let 3x = a , and 5y = b so we have to simplify:

(a+b)² + (a-b)²

= ( ​a² + b² + 2 a b ) + ( a² + b² - 2 a b )

= 2 ( a² + b² )

So we have :

(3x+5y)² +(3x-5y)²​ = 2 { (3x)² + (5y)² }

= 2 { 9 x² + 25 y²}

= 18 x² + 50 y²