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3 years ago

Two times one number added to three times a second number is 21.

Mathematics

1 answer:

Daniel [21]3 years ago

3 0

Answer:

Step-by-step explanation:

"Two times one number added to three times a second number is 21.

2x + 3y = 21

"The second number is ten less than five times the first number"

y = 5x-10

Substitution

2x+3(5x-10) = 21

2x + 15x - 30 = 21

17x = 51

x = 3

y = 5x-10 = 5

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ahrayia [7]

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2 years ago

Fiesta28 [93]

A.) 135 miles in 3 hours = 45 miles per hr

B.) 22 miles in 1 hour= 22 miles per hr

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3 years ago

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Arada [10]

Answer:

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3 years ago

What is a histogram?

aliya0001 [1]

Answer:

a diagram consisting of rectangles whose area is proportional to the frequency of a variable and whose width is equal to the class interval.

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3 years ago

What is the dimension of a rectangle if the perimeter is 198

AfilCa [17]

Answer:

Length = 49.5 unit and width = 49.5 unit

Step-by-step explanation:

Given as , Perimeter of rectangle = 198 unit

so ,as Perimeter of rectangle = 2× ( Length + width)

Or, 198 = 2 × (Length + width)

Or, $\frac{198}{2}$ = length + width

So, length + width = 99 unit

Now to make area maximum

Length × width = maximum

Or, (99 - width ) × width = maximum

99 Width - width² = maximum Let width = W

Now differentiate both side with respect to W

D(99W - W²) $\frac{D(99w - w^2)}{Dw}$ = 0 as, constant diff is 0

So, 99 - 2w = 0

Or, w = $\frac{99}{2}$

Or, w = 49.5 unit and L = 99- 4905 = 49.5 unit Answer

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3 years ago