Question

Б) (у-3х)2 -(3х+у)(у-3х)

Answer 1

(y-3x)2-(3x+y)(y-3x)=2y-6x-(3xy-9x в кв+ у в кв -3ху)= 2у-6х-3ху+9х в кв-у в кв+ 3 ху= 2у-6х+9х в кв - у в кв

Answer 2

To simplify the given expression, let's expand it step by step:

Expression: (у - 3х)² - (3х + у)(у - 3х)

Step 1: Expand (у - 3х)² (у - 3х)² = (у - 3х)(у - 3х) Using the formula (a - b)² = a² - 2ab + b²: (у - 3х)² = у² - 2 * у * 3х + (3х)² (у - 3х)² = у² - 6ху + 9х²

Step 2: Expand (3х + у)(у - 3х) (3х + у)(у - 3х) = 3х * у + 3х * (-3х) + у * у + у * (-3х) (3х + у)(у - 3х) = 3ху - 9х² + у² - 3ху (3х + у)(у - 3х) = у² - 9х²

Now, let's put both results together:

Expression: (у - 3х)² - (3х + у)(у - 3х) Expression = (у² - 6ху + 9х²) - (у² - 9х²)

Now, let's simplify by removing the parentheses:

Expression = у² - 6ху + 9х² - у² + 9х²

Step 3: Combine like terms:

The у² terms cancel each other out: Expression = -6ху + 9х² + 9х² Expression = -6ху + 18х²

So the simplified expression is -6ху + 18х².