The temperature was recorded for four straight days. The temperatures was recorded for the first three days were -2°,10°,and 7°.What must be the temperature recorded on the fourth day if the total temperature change was -4°?

Step-by-step explanation:

Let x represent temperature on 4th day.

We have been given that the temperatures was recorded for the first three days were -2°,10°,and 7°.

The total temperature on f days would be .

We have been given that total temperature change was -4°. We can represent this information in an equation as:

Therefore, the temperature on 4th day must be equal to .

x = -3

y = -18

step-by-step explanation:

to solve by substitution, substitute one variable and solve for the other. then substitute again to find the remaining variable.

x-1/3(3x-9) = -3 since y=3x-9 substittute y.

x-1/3(3x-9)=-3

x + x +3 = -3

2x+3=-3

2x+3-3= -3-3

2x=-6

x=-3

substitute again into y=3x-9

y=3(-3)-9

y=-9-9

y=-18