Ken moved 7 to the right which is correct because he needs to get 7º higher, but when he moved 2º to the left that would be a temperature decrease which is is incorrect.
Sample Response: Ken’s error was showing a decrease in temperature by moving 2 units left on the number line. He should have moved 2 units right to represent an increase in temperature of 2°C.
Honestly this problem you can use both x and y but x tends to be the easier one to use and i would use the first equation because it is easier to solve because all the numbers are even.<span />