Homework #74

Write a two-step equation involving division and addition that has a solution of x=25

zavuch27 [327]

If this is what you mean..?

In order to do this you would work backward from the answer.
You have x = 25 and ant to include and addition. As we are working backwards, we use the opposite operation to addition - subtraction. We'll make it an easy number so we will subtract 15 to get to 10.
So far it looks like 10 = 15 + x
Now, to include a division, we want to do the opposite again, multiplication. Pick any number to multiply 10 by - for this example we'll choose 7.
7 x 10 = 70
Now we can write out the equation -
70/7 + 15 = x
No brackets are required as Division comes before addition in BIDMAS.

An alternate choice would be to have x the other side of the '='

To do this, multiply x by a number of choice (for example 3) to make the divison section of the equation. This makes 75. This can be written as a fraction. 75/x = 3
Next, for the addition, whatever happens on one side, the exact same happens on the other. Pick any number to add on (e.g. 5) and re-write the equation.
75/x + 5 = 8

Sorry if this doesn't make perfect sense

4 0

4 years ago

30 divided by 2438 long division

Ksju [112]

The answer would be 81.3

6 0

3 years ago

Read 2 more answers

Explain why x squared -8x+20 is always positive

Tpy6a [65]

Answer:

to square a number you multiply the number by itself.

a positive number times a positive number is a positive number.

a negative number times a negative number is a negative number.

and if you are multiplying 2 numbers with the same sign they will always be a positive number.

3 0

3 years ago

Points that don't belong to any line

svetlana [45]

Answer:

Noncollinear points

Step-by-step explanation:

Collinear points lie on the same line. Noncollinear points are the opposite.

3 0

2 years ago

How do you solve this?

puteri [66]

Answer:

Width: 7

Length: 14

Step-by-step explanation:

The area of a rectangle can be found my multiplying the length by the width. We do not know neither the length nor the width. However, we do know that the length is 7 feet longer than the width. Because we do not know the value of either side, let's let $x$ represent the width.

Since the length is 7 feet longer, we can represent the length by $x+7$ .

Now that we have our values for the length and the width we can multiply them together to find our area.

$(x)(x+7)=x^{2} +7x$

Now we have our equation, so we can address the changes made by the original question. The original question states that when 7 is added to both the length and width the area becomes 3 times larger. To do so simply increase each side by 7 by adding 7 to the original values.

$(x+7)(x+14)$

And multiply our area by 3.

$3(x^{2} +7x)$

set these equal to each other to find your new equation.

$(x+7)(x+14)=3(x^{2} +7x)$

Now you need to solve for $x$ . To do this first muliply $(x+7)$ and $(x+14)$ .

$(x+7)(x+14)=\\x^{2} +14x+7x+98=\\x^{2} +21x+98$

Then multiply $3(x^{2} +7x)$

$3(x^{2} +7x)=\\3x^{2} +21x$

Now you can begin solving for $x$ .

$x^{2} +21x+98=3x^{2} +21x$

Subtract $x^{2}$ from both sides.

$21x+98=2x^{2} +21x$

Subtract $21x$ from both sides.

$98=2x^{2}$

Divide by 2.

$49=x^{2}$

And finally take the sqaure root of both sides.

$\sqrt{x^{2} }=\sqrt{49}\\x=7$

Remember, because we are dealing with length, there cannot be negative. So while normally we would get both +7 <em>and</em> -7, in this case we <em>only </em>get +7.

Now that we have the value of $x$ , we can plug it into our original values.

For width we simply get 7.

For length we get 7+7=14

To check our answer we cna multiply 7 by 14 to get 98. Then we can add 7 to our length and width to get 14 and 21. Multiply these together and we get 294. 294 divided by 3 is 98, proving our answer correct.

7 0

4 years ago