Tutorial

Topic : Identities

Using the identity (a-b)²=a²-2ab+b² and simply (3x-5y)²

Step 1 : (3x-5y)² (Given Question, Here a = 2x, b = 5)

Step 2 : (3x-5y)² = (3x)²-2x3xx5y+5y² (Compare and Substitute in the given formula or identity)

Step 3 : 9x² - 30x + 25y² (Here the first term becomes (3x)² = 3x x 3x=9x², Next term becomes 2x3xx5y = 30xy, the last term becomes 5y²=5yx5y=25y²)

Step 4 : Therefore 9x²-30x+25y² is the answer.

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