Question

The temperature Saturday is -13°, and on Sunday it is -4°. Which equation would be used to show the difference in temperature from Saturday to Sunday?
-4 + 13 =
-4 - (-13) =
-4 - 13
4 + (-13)

Answer 1

to change the temperature from -13 on Saturday to -4 on Sunday, you would need to add 9 degrees ( -13 + 9 = -4 )

 so you need the equation that would also = 9

-4 + 13 = 9

-4 - (-13) = 9

-4 -13 = -17

4 +(-13)= -9

 there are 2 equations that equal the correct change in temperature, but since both temperatures are negative ( -13 & -4)

 the correct equation would also contain 2 negative numbers

 so correct equation should be: -4-(-13) =

Answer 2

-4 - (-13) = 9 is the answer