Question

First correct answer= brainlist

Answer 1

Answer:

$-a^2+ab$

Step-by-step explanation:

So the sentence can be written like this:

$((a^2-b^2)+(a^2+ab+3b^2))-((a^2-2ab+b^2)+(2a^2+2ab+b^2))$

Now you can combine like terms in the first part of the equation and the second part:

$((a^2+a^2)+ab+(-b^2+3b^2))-((a^2+2a^2)+(-2ab+2ab)+(b^2+b^2))$

Which leaves you with:

$(2a^2+ab+2b^2)-(3a^2+2b^2)$

Now distribute the negative to the second part of the equation:

$2a^2 + ab + 2b^2-3a^2-2b^2$

Combine like terms again:

$(2a^2-3a^2)+ab+(2b^2-2b^2)$

Which becomes:

$-a^2+ab$

Answer 2

Answer:

- a² + ab

Step-by-step explanation:

summing the first 2 expressions

a² - 2ab + b² + 2a² + 2ab + b² ← collect like terms

= 3a² + 2b² → (1)

summing the next 2 expressions

a² - b² + a² + ab + 3b² ← collect like terms

= 2a² + ab + 2b² → (2)

Subtracting (1) from (2)

2a² + ab + 2b² - (3a² + 2b²) ← distribute parenthesis by - 1

= 2a² + ab + 2b² - 3a² - 2b² ← collect like terms

= - a² + ab