Question

If a ∆ b = ab + a² + b² - a + b and a & b both ar integers, find (-7) ∆ (-5)

I don't know what is the answer, it's my doubt. please help​

Answer 1

$- 7 \times - 5 + - 7 ^2 + - 5 ^2 + + 7 + - 5$

$35 + 49 + 25 + + 2$

$111$

Answer 2

$\huge\colorbox{red}{A}\colorbox{lime}{n}\colorbox{cyan}{S}\colorbox{orange}{w}\colorbox{blue}{E}\colorbox{violet}{r}$

$- 7 \times - 5 + - 7 ^2 + - 5 ^2 + + 7 + - 5$

j