Answer:
to find the answer for 1 pencil you just need to divide
Step-by-step explanation:
3.20$ divide by 4=0.8 /each pencil cost 0.8
4.80$ divide by 12=0.4 /each pencil cost 0.4
Could just be used as a variable.
A would be your answer.
(I am going to assume that the set of numbers are multiplied by exponents.)
To solve you just need to calculate each one. Note that for positive exponents you move the decimal point to the right and negative exponents you move the decimal point to the left.

The first scientific notation would be equal to 2700 because you move the decimal point 3 places to the right, since the exponent is positive.

The second scientific notation would be equal to 0.00424 because you move the decimal point 3 places to the left, since the exponent is negative.

The third scientific notation would equal 470 because you move the decimal point 2 places to the right, since the exponent is positive.

The last scientific notation would equal 0.043 because you move the decimal point 2 places to the left, since the exponent is negative.

Answer:
Step-by-step explanation:
f(x) = a(x-p)(x-9) is the equation of a vertical parabola.
If a>0, the parabola opens upwards.
If a<0, the parabola opens downwards.
Also, the focal length of the parabola is 1/|4a|.