Answer:
y-10 = -1 * x+ (-4)
Step-by-step explanation:
Answer: 15.7828283 miles
Step-by-step explanation: 5280*12 = 63360. There are 63360 inches in 1 mile. 1000000/63360=15.7828283
Answer: 81.2
Step-by-step explanation:
h(t) = -5t² + 40t + 1.2
h(4) = -5(4)² + 40(4) + 1.2 We plug 4 seconds as t, and solve h(4)
h(4) = -80 + 160 + 1.2
h(4) = 80 + 1.2
h(4) = 81.2
Answer:
0.67 cm/s
Step-by-step explanation:
The area of a square is given by :
....(1)
Where
x is the side of a square
Differentiating equation (1) wrt t.
When A = 81cm², the side of the square, x = 9 cm
Put all the values,
So, the length of the side of a square is changing at the rate of 0.67 cm/s.
Answer:
as written: 2500.2
as intended: 3000
Step-by-step explanation:
20% = 0.2, so adding 0.2 to 2500 gives 2500.2
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We suspect you want to add 20% of 2500 to 2500. That is ...
2500 + 20%×2500
= 2500 + 0.20×2500
= 2500 + 500
= 3000
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<em>Comment on percentages</em>
A percentage is a pure number. It is a ratio of like quantities, so has no units.* A <em>useful</em> percentage always has a base. That is, it is a percentage <em>of something</em>. Sometimes that base may be unclear or unstated, in which case the percentage might very well be considered to be meaningless.
In any event, a percentage is simply a (unitless) fraction. The "%" symbol means the same thing as "/100", so 20% means 20/100 = 2/10 = 1/5.
The very clear math expression 2500 +20% means simply 2500 + 1/5, which is the mixed number 2500 1/5 or the decimal value 2500.2. Usually, when we want to add a percentage to some value, we want the percentage to be <em>of the original value</em>. When that is written as a math expression, it must show this:
2500 + 20% of 2500
2500 + 20%×2500
2500(1 +20%)
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* The concentration or potency of some medicines or other mixtures may be expressed as a percentage that is the ratio of one unit to a different unit, typically weight per volume. That is, a "0.1%" preparation may be 0.1 grams per 100 mL, for example. You have to read the label to determine whether this is the case. Mathematically, this is not a percentage, but is a non-standard use of the "%" symbol to indicate a ratio to 100 of something.
