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2 years ago

Alex simplified the expression 7+(3x 1. 4)+5+2+(5x1. 4) to find the area of the figure on the grid.

1 answer:

3 0

The error Alex made while simplifying the expression 7+(3x 1. 4)+5+2+(5x1. 4) is "he found the perimeter of the figure instead of the area".

<h3>How to find area of an object?</h3>

The area of an object is the product of the length and width of the objects.

Alex added the dimensions of the grid instead of multiplying them.

7+(3x 1. 4)+5+2+(5x1. 4)

For instance,

Area of a rectangle = length × width
Perimeter of a rectangle = 2(length + width)

Therefore, Alex found the perimeter of the figure instead of the area".

Learn more about area:

brainly.com/question/13048427

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X+a=b please urgent answer

atroni [7]

Answer:

Step-by-step explanation:

8 0

2 years ago

The sum of the tens digit and the hundreds digit of a number is three times the units digit. 1/5 of the sum of all three digits

Crazy boy [7]

Answer: The numbers are:

965

875

785

695

Step-by-step explanation:

We have a 3 digit number that can be written as:

a*100 + b*10 + c

Where a, b, and c are single-digit numbers.

a is the hundreds

b is the tens

c is the unit.

We know that:

"The sum of the tens digit and the hundreds digit of a number is three times the units digit."

a + b = 3*c

" 1/5 of the sum of all three digits is 1 less than the units digit."

(a + b + c)/5 = c - 1

Then we have the two conditions:

a + b = 3*c

(a + b + c)/5 = c - 1

From the first one, we can write:

(a + b)/3 = c

Replacing that in the other equation we get:

(a + b + a/3 + b/3)/5 = a/3 + b/3 - 1

(4/3)*(a + b)/5 = (a/3 + b/3) - 1

(4/15)*(a + b) = (a + b)/3 - 1

(4/15)*(a + b) - (a + b)/3 = - 1

-(1/15)*(a + b) = -1

a = 15 - b

Then we can give different values for b, and find the values of a and c, where a and c must be positive.

b = 9

a = 15 - 9 = 6

Then:

c = (9 + 6)/3 = 5

(notice that a + b = 15, then c will be always equal to 5, reggardless of the values of b and a).

This number will be:

695.

if b = 8, then:

a = 15 - 8 = 7

and c = 5, same as before.

the number is 785.

If b = 7, then:

a = 15 - 7 = 8

The number is 875

if b = 6, then:

a = 15 - 6 = 9

The number is:

965

4 0

2 years ago

A scientist has a container of 2% acid solution and a container of 5% acid solution. How many fluid ounces of each concentration

algol [13]

Let 'a' be the number of ounces of 2%-solution in the 25-ounce mixture

and 'b' be the number of ounces of 5%-solution in the 25-ounce mixture.

Since, fluid ounces of each concentration should be combined to make 25 fl oz.

So, a+b=25 (Equation 1)

And, a container of 2% acid solution and a container of 5% acid solution should be combined to make 25 fl oz of 3.2% acid solution.

So, a of 2% + b of 5% = 3.2% of 25

$(a \times \frac{2}{100})+(b \times \frac{5}{100})= 25 \times \frac{3.2}{100}$

$(0.02a)+(0.05b)= 0.8$

Multiplying the above equation by 100, we get

$2a+5b=80$ (Equation 2)

Substituting the value of a=25-b in equation 2, we get

$2(25-b)+5b=80$

$50-2b+5b=80$

$50+3b=80$

$3b=30$

$b=10$

Since, a=25-b

a= 25-10

a=15.

So, 15 fluid ounces of 2% solution combined with 10 ounces of the 5% solution to create a 25-ounce mixture at 3.2% concentration of acid.

7 0

2 years ago

The steps for determining the center and radius of a circle using the completing the square method are shown below:

Fudgin [204]

The answer is option c.
That is, the wrong step in step 6. It was written that the center of the circunference is the point (2.1). However, the general equation of a circumference is:
(X- (a)) ^ 2 + (Y- (b)) ^ 2 = r ^ 2
Where the point (a, b) is the center of the circle.
So for this case the point for the center is: (-2, -1)

7 0

3 years ago

A firm has the marginal-demand function where D(x)=-1400x÷√25-x² is the number of units sold at x dollars per unit. Find the dem

borishaifa [10]

The equation of the demand function is D(x) = 1400√(25-x²) + 11400

<h3>How to determine the demand function?</h3>

From the question, we have the following parameters that can be used in our computation:

Marginal demand function, D'(x) = -1400x÷√25-x²

Also, we have

D = 17000, when the value of x = 3

To start with, we need to integrate the marginal demand function, D'(x)

So, we have the following representation

D(x) = 1400√(25-x²) + C

Recall that

D = 17000 at x = 3

So, we have

17000 = 1400√(25-3²) + C

Evaluate

17000 = 5600 + C

Solve for C

C = 17000 - 5600

So, we have

C = 11400

Substitute C = 11400 in D(x) = 1400√(25-x²) + C

D(x) = 1400√(25-x²) + 11400

Hence, the function is D(x) = 1400√(25-x²) + 11400