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1 year ago

The sum of 2, 6, and a number amounts to 15. Find the number.

1 answer:

8 0

Given the numbers, let’s set up an equation:

2 + 6 + n = 15

We can solve this using steps:

1. Simplify

8 + n = 15

2. Subtract 8 from both sides

(8 - 8) + n = 15 - 8

3. Simplify

n = 7

Let’s plug in 7 to see if it makes sense:

2 + 6 + 7 = 15

Because this equation is true, we have found our number.

Our unknown number is 7.

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Work out the area of a parallelogram of base 5m and height 3m

Arada [10]

B*H= area so 3*5= 15

15 is your answer

6 0

3 years ago

A line with a slope of 0.20 passes through

zaharov [31]

Answer:

y=0.2x-20

Step-by-step explanation:

1) the common view of the line in the slope-intercept form is:

y=s*x+i, where s - the value of the slope (it is 0.2 according the condition), i - the value of intercept (to be calculated);

y=0.2*x+i.

2) if to substitute the given coordinates (1.25;-17.5) into the common view, then:

-17.5=1.25*0.2+i;

it is possible to calculate the value of 'i': i= -20.

3) if the slope=0.2, the intercept= -20, then the required equation of the line is:

y=0.2x-20.

8 0

3 years ago

Do all animals have the same life span. Explain your answer

Talja [164]

No, because every animal is different.

5 0

3 years ago

Suppose that the amount of time it takes to build a highway varies directly with the length of the highway and inversely with th

KatRina [158]

Answer:

21 weeks

Step-by-step explanation:

In this question, we are to use proportionality to find the solution to the question.

We were made to know that the time taken to build the highway is varied directly with the length and inversely with the number of workers.

Let us make a mathematical representation for this.

Let the time be t, number of workers be w and length be l

t is directly proportional to l and inversely proportional to w

Mathematically;

t = kl/w

Where k is the constant of proportionality.

Let’s find the value of k

150 workers built 12 miles of highway in 14 weeks ; plug these in the equation to get k

14 = k * 12/150

k = 150 * 14/12 = 175

Now we want to get t given w and l

from ;

t = kl/w

We can get t; where l = 15 and w = 125

t = 175 * 15/125

t = 21 weeks

4 0

3 years ago

Read 2 more answers

A rectangle has its base on the x axis and its upper two vertices on the parabola y = 9 − x2. (a) Draw a graph of this problem.

gtnhenbr [62]

Answer:

(a) see attached
(b) width: 2x; height: y = 9-x²
(c) A=2x(9-x²) . . . 0 ≤ x ≤ 3
(d) dA/dx = -6x² +18; x=±√3
(e) 12√3 units²

Step-by-step explanation:

(a) The attachment shows the graph of the parabola in blue. It also shows an inscribed rectangle in black.

(b) The upper right point of the rectangle is shown in the attachment as (x, y). The dimension y is the height of the rectangle. The x-dimension is half the width of the rectangle, which is symmetrical about the y-axis. Hence the width is 2x.

(c) As with any rectangle, the area is the product of length and width:

... A = (2x)(9 -x²) . . . . . the attachment shows a graph of this

... A = -2x³ +18x . . . . . expanded form suitable for differentiation

A suitable domain for A is where both x and A are non-negative: 0 ≤ x ≤ 3.

(d) The derivative of A with respect to x is ...

... A' = -6x² +18

This is defined everywhere, so the critical values will be where A' = 0.

... 0 = -6x² +18

... 3 = x² . . . . . . . divide by -6, add 3

... √3 = x . . . . . . . -√3 is also a solution, but is not in the domain of A

(e) The rectangle will have its largest area where x=√3. That area is ...

... A = 2x(9 -x²) = 2√3(9 -(√3)²) = 2√3(6)

... A = 12√3 . . . . square units . . . . ≈ 20.785 units²

7 0

3 years ago