I believe the answer is A. 40.
I would substitute y = x^2
4y^2 -21y+20=0
Answer:
6 kg/m
Step-by-step explanation:
mass m = 3x^2.
rho ρ= dm/dx =6x
ρ(1) =6 Kg/m
linear density is the derivative of mass (m) with respect to position(x)
that is how fast is the mass changing at that position.
Using proportions, it is found that she will pay $8.28 in total after the discount.
<h3>What is a proportion?</h3>
A proportion is a fraction of a total amount, and the measures are related using a rule of three.
Before tax, the total price is given by:
P = 3.59 + 4.25 + 3.99 = $11.83.
She gets a 30% discount, hence the proportion she pays is 70% of this amount, hence:
P = 0.7 x 11.83 = $8.28.
She will pay $8.28 in total after the discount.
More can be learned about proportions at brainly.com/question/24372153
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