3. The time, T seconds, it takes a water heater to boil some water is directly proportional
to the mass of water, mkg, in the water heater.
When m= 250, T = 600
(a)
Find T when m= 400
T=
(3)

T = 960 seconds

Step-by-step explanation:

the equation of the direct proportion is y = k x, where k is the constant of variation, we find it using the initial amount of x and y

∵ T is the time in seconds

∵ m is the mass of water in kg

∵ The time, T it takes a water heater to boil some water is directly

   proportional to the mass of the water, m

∴ T = km

∵ When m = 250 kg, T = 600 seconds

→ Substitute them in the equation above to find k

∵ 600 = k(250)

→ Divide both sides by 250 to find k

∴ 2.4 = k

→ Substitute the value of k in the equation above

∴ T = 2.4m ⇒ the equation of the direct proportion

∵ m = 400 kg

→ Substitute it in the equation of variation to find T

∵ T = 2.4(400)

∴ T = 960 seconds

answer:

(-8,7)

explanation:

we know that  

f

(

−

3

)

=

7

therefore, if we wish to get the output as 7, in the function, we need to have our input to be -3.

looking at the function  

f

(

x

+

5

)

, what should the value of x be, such that the input in the function becomes 7?

we simply equate the terms,

x

+

5

=

−

3

x

=

−

8

thus, the point on the new function would be  

(

−

8

,

7

)

answer: the answer is fre sha voca do

step-by-step explanation: