Get a hint and tell me when you get a hint of where the x and I’ll tell you

Then, now that we have solved for T, we can evaluate and solve for t=20 minutes.
Answer:
f(x)=11+7√x
f'(x)=7/(2x^(1/2))
putting x=1
f'(1) = 7/(2×1^(1/2))
= 7/2 = 3.5
putting x=2
f'(2) = 7/(2×2^(1/2))
= 7/(2×√2)
= 7√2/4
= 2.47 (rounded to the nearest hundredth)
f'(3) = 7/(2×3^(1/2))
= 7/(2×√3)
= 7√3/6
= 2.02 (rounded to the nearest hundredth)
Answer:
He would have to pay $25.75

C is cost, p is pounds
6.75 per pound minus 1.25 with the coupon and you get the cost.

the domain:

the equation:

4 is in the domain
-2 is not in the domain
The answer:

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Also, the answer in 13 is {8}. -3 is not in the domain. Replace x with -3 and you'll see:

It's not true so -3 isn't a solution to this equation.