John G. answered • 04/03/16
Tutor
4.8
(52)
Understanding math via the real world.
Multiplication comes first, then when deciding between addition and subtraction go from left to right.
So 4x5 = 20, now we have 4 - 20 + 3.
4 - 20 = -16, so now -16 + 3 = -13.
You can also think of the 4 - 20 + 3 as a positive 4, a negative 20, and a positive 3, and then add them all up. You just don't want to fall into the trap of 20 + 3 = 23.
