Answer:
We have the same homework!!!!
hours that passed= 10
Step-by-step explanation:
(1st step)We start with the expression:
(1st)82-0.4x=78
"STARTED at 82 degrees" 82
"Cooling DOWN 0.4 degrees" -0.4
"EACH hour" x
"NOW 78 degrees" =78
(2nd step) We want to get the variable x alone, so we have to do the opposite sign they have, to cancel the number out for it to be 0.
(1st) 82 -0.4x =78
(2nd) -82 ÷-0.4 =78
(3rd)Now, you work out the problem (transfer the numbers from the left to the right). First, you have to do the subtraction sign, not sure why.
(1st) 82 -0.4x =78
(2nd) -82 ÷-0.4 =78
(3rd) 78 -82= -4
-4÷-0.4= 10
X= 10
there you have it!
To make sure this is correct, you do the following.
82 -0.4 x 10
Solve using PEMDAS
-0.4 x 10 = -4
its time to add 82.
82 - 4 = 78
78 is the exact temperature that was said in the problem
