70% of what number is 21?

Mathematics

2 answers:

Shtirlitz [24]2 years ago

5 0

The first answer is 30
21 x 10 = 210
210 ÷ 7 = 30

Answer: 6.57

60% of 90 =54

harina [27]2 years ago

4 0

1. 30

21 x 100 = 2,100

2,100 ÷ 70 = 30
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2. 6.57

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3. 54

90 x 60 = 5,400

5,400 ÷ 100 = 54
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Hope this helped. Have a great day!

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Video Example EXAMPLE 1 Find the linearization of the function f(x) = x + 1 at a = 3 and use it to approximate the numbers 3.98

Blizzard [7]

Answer:

the linearization is y = 1/4x +5/4

the linearization will produce <em>overestimates</em>

the values computed from this linearization are ...

f(3.98) ≈ 2.245

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Step-by-step explanation:

Apparently, you have ...

$f(x)=\sqrt{x+1}$

from which you have correctly determined that ...

$f'(x)=\dfrac{1}{2\sqrt{x+1}}$

so that f(3) = 2 and f'(3) = 1/4. Putting these values into the point-slope form of the equation of a line, we get the linearization ...

g(x) = (1/4)(x -3) +2

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The values from this linearization will be overestimates, as the curve f(x) is concave downward everywhere. The tangent (linearization) is necessarily above the curve everywhere.

At the given values, we find ...

g(3.98) = 2.245

g(4.05) = 2.2625