70% of the students pack there lunches. 14/20 = 7/10 = 0.7
Answer: Seven ate Nine
Step-by-step explanation:
Answer:
D 17 1/4
Step-by-step explanation:
9514 1404 393
Answer:
a) average rate = (total distance)/(total time)
b) Rave = 2·R1·R2/(R1 +R2)
c) cheetah's average rate ≈ 50.91 mph
Step-by-step explanation:
a) Let AB represent the distance from A to B. Let t1 and t2 represent the travel times (in hours) on leg1 and leg2 of the trip, respectively. Then the distances traveled are...
First leg distance: AB = 70·t1 ⇒ t1 = AB/70
Second leg distance: AB = 40·t2 ⇒ t2 = AB/40
The average rate is the ratio of total distance to total time:
average rate = (AB +AB)/(t1 +t2)
average rate = 2AB/(AB/70 +AB/40) = 2/(1/70 +1/40) = 2(40)(70)/(70+40)
average rate = 560/11 = 50 10/11 . . . mph
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No equations are given, so we cannot compare what we wrote with the given equations. In each step of the solution, we have used the rules of algebra and equality.
b) For two rates over the same distance (as above), the average is their harmonic mean:
average rate = 2r1·r2/(r1+r2)
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c) The cheetah's average rate was 50 10/11 mph ≈ 50.91 mph.
Answer:
d.
Step-by-step explanation:
To convert a root to a fraction in the exponent, remember this rule:
![\sqrt[n]{a^{m}}=a^{\frac{m}{n}}](https://tex.z-dn.net/?f=%5Csqrt%5Bn%5D%7Ba%5E%7Bm%7D%7D%3Da%5E%7B%5Cfrac%7Bm%7D%7Bn%7D%7D)
The index becomes the denominator in the fraction. (The index is the little number in front of the root, "n".) The original exponent remains in the numerator.
In this question, the index is 4.
The index is applied to every base in the equation under the root. The bases are 16, 'x' and 'y'.
![\sqrt[4]{16x^{15}y^{17}} = (\sqrt[4]{16})(\sqrt[4]{x^{15}})(\sqrt[4]{y^{17}}) = (2)(x^{\frac{15}{4}}})(y^{\frac{17}{4}}) = 2x^{\frac{15}{4}}}y^{\frac{17}{4}}](https://tex.z-dn.net/?f=%5Csqrt%5B4%5D%7B16x%5E%7B15%7Dy%5E%7B17%7D%7D%20%3D%20%28%5Csqrt%5B4%5D%7B16%7D%29%28%5Csqrt%5B4%5D%7Bx%5E%7B15%7D%7D%29%28%5Csqrt%5B4%5D%7By%5E%7B17%7D%7D%29%20%3D%20%282%29%28x%5E%7B%5Cfrac%7B15%7D%7B4%7D%7D%7D%29%28y%5E%7B%5Cfrac%7B17%7D%7B4%7D%7D%29%20%3D%202x%5E%7B%5Cfrac%7B15%7D%7B4%7D%7D%7Dy%5E%7B%5Cfrac%7B17%7D%7B4%7D%7D)
To find the quad root of 16, input this into your calculator. Since 2⁴ = 16, ![\sqrt[4]{16}](https://tex.z-dn.net/?f=%5Csqrt%5B4%5D%7B16%7D)
= 2.
For the "x" and "y" bases, use the rule for converting roots to exponent fractions. The index, 4, becomes the denominator in each fraction.
