Simplify the expression 8xy + 6.3h + 7xy - xy - 2h

The mean temperature for the first 4 days in january was 7°c. the mean temperature for the first 5 days in january was 5°c. what was the temperature on the 5th day?

X+ y = 5 ; x - y =3 solve using linear combination

The moats separating people from the animals are 5 m wide for lions and 4 m wide for the elephants. if the lion’s moat is 4 m deep, how deep should the elephants’ moat be?