Question

$(3a^2-b2+2ab)-(a^2+b^2+ab)$
pls help write with explanation​

Answer 1

Answer :

In the attachment

Steps followed :

1. We have written the given Question in column form .
2. Then we tried to change the signs of the lower part . Any sign in lower part changes to opposite form . Like (+) becomes (-) and (-) becomes (+) . So we changed the signs .
3. Then we simplified the terms using simple mathematical operations like :

• + , + = +
• + , - = -
• - , + = -
• - , - = +

So finally we get 2a² - 2b² + ab

Answer 2

Answer :-

★ The required simplification is as follows :-

✒ 2a² - 2b² + ab

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★ Aid to Memory :-

Here the concept of Algebraic identity of quadratic equations has been used . First by applying proper signs, we must open both the brackets and then solve the equation.

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★ Solution :-

Given,

✏ (3a² - b² + 2ab) - (a² + b² + ab)

By opening the bracket, we get,

✏ 3a² - b² + 2ab - a² - b² - ab

On rearranging, we get,

✏ 3a² - a² - b² - b² + 2ab - ab

✏ 2a² - 2b² + ab

We clearly see that, no identity is possible here to combine all. So our final answer is

✏ 2a² - 2b² + ab

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★ More to know :-

• Here we are using sign convention. This is as follows,

=> (+) ×/÷ (-) = (-)

=> (+) ×/÷ (+) = (+)

=> (-) ×/÷ (-) = (-)

=> +, - = -

=> -, - = +

=> +, + = +

=> -, + = -

• Some, identities are :-

=> a² + b² + 2ab = (a + b)²

=> (a - b)² = a² - 2ab + b²

=> (a + b)(a - b) = a² - b²

=> a² - b² = (a + b)² - 2ab