Question

Please see attachment

this makes no sense to me!


(-7) + (2) = -5 in my world

- oh woops - its (-7) - (2) = -9 which does makes sense

Answer 1

it’s all about substitution. you need to substituse (1,5) so 1 is x and 5 is y. you put it as 7(1) - 2(5) = -5 and you solve