Answer :
a. 7 hours ago the temperature was 7 * 1,5 = 10,5 degrees more, so if now it's 0, then it was 10,5 degrees 7 hours ago.
b. in six hours it will be 6 * 1,5 = 9 degrees less, so if it's 0 now, then it will be -9 degrees in 6 hours.
c. the temperature was reading 6 degrees 4 hours ago because:
x * 1.5 = 6 / ÷1.5 (both sides)
x = 4
d. -8 is expected to be in 5 hours and 15 minutes because:
x * 1.5 = 8 / ÷1.5 (both sides)
x = 5 1/3
b. in six hours it will be 6 * 1,5 = 9 degrees less, so if it's 0 now, then it will be -9 degrees in 6 hours.
c. the temperature was reading 6 degrees 4 hours ago because:
x * 1.5 = 6 / ÷1.5 (both sides)
x = 4
d. -8 is expected to be in 5 hours and 15 minutes because:
x * 1.5 = 8 / ÷1.5 (both sides)
x = 5 1/3