A scientist is measuring the temperature change in a decimal compound. The temperature dropped 11 f per hour from the original temperature. After four hours the temperature was 90 f find the compounds original temperature.

From the info given we know that m =-11 and we have a condition given:

Using this condition we have:

And solving for b we got:

So then the original temperatue for this case is 134 F

Step-by-step explanation:

For this case we know that after four hours the temperature was 90 f and the temperature dropped 11 f per hour.

We can use a linear model to solve the problem given by:

Where F represent the temperature, t the time in hours and m the slope and b the intercept.

From the info given we know that m =-11 and we have a condition given:

Using this condition we have:

And solving for b we got:

So then the original temperatue for this case is 134 F

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