1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
QveST [7]
3 years ago
13

One number is 10 more than another number. If the product of the two numbers is -21 find both numbers

Mathematics
1 answer:
sergeinik [125]3 years ago
8 0

Answer:

The Two numbers are 7 and -3.

Step-by-step explanation:

For this problem, the first thing we need to do is rewrite what we are given in mathematical terms, or equations that we can use to solve our problem at hand. We can say that:

X = <em>"one number" </em>

and

X+10 = <em>"our other number".</em>

then with our given information and newly defined mathematical terms, we would then combine both of them and formulate it into an equation that we can use to find the two numbers:

= x(x+10) = -21   (Next, we expand this equation to:) --->

=  X2+10x-21=0  (Side Note: the "x2" is x squared.).

= X2+10x-21 = 0  (add 21 to the other side to get)

= X2+10x +21 = 0  (this is the equation that we will use to find the two numbers)

Next step is to solve by factoring the equation X2+10x+21=0

An easy way to approach factoring an equation of this format is to think..

"<em>What two numbers can add up to equal ten? (10x) and also multiply to equal 21 (+21) ? "</em>

In our case, our two numbers are 7 and 3. (Because 7 plus 3 equals ten, and also 7 times 3 equals 21.)

So, with that information, : X2+10x+21 factored equals  

(x+3)(x+7) = 0.

Next, we set both X+3 and X+7 equal to zero and solve for x to find the two numbers

= ( x+3) = 0   (3-3 = 0   0-3 = -3), so,  X= -3        

= (x+7) = 0 (7-7 = 0  0-7 = -7), so, X = -7

So with the work above we found the two numbers we need, However, the question specifically stated that the product of the two numbers is negative 21, and we currently have positive 21 (Because neg 7 times neg 3 = positive 21).

So, with this, our last step is to use one of the two numbers that we found (X= -3 or X= -7) in the second equation that we made in the beginning to find the last number that we need.

We know that a negative number times a positive number equals a negative number, so with this fact in mind, we revisit one of our first equations while keeping our original question in mind that:

<em>"one number is </em><em>10</em><em> more than another number "</em>

With that in mind, the only combination that has the highest chance of working in accordance to the question we have is:

X=-3

So based on that observation, we have assumed that -3 is our first number. We need to <em>prove</em> that it is the right number by plugging it into the equation below:

So, if we plug in -3 in our equation that we made in the beginning (X+10 = "our other number"), then we find:

= -3+10 = 7  which is our second and final number!

Therefore, the two numbers are 7 and -3 because 7 is 10 more than -3,

and the product of both numbers are -21.

 

I hope this helps,  Thanks for your time!  

You might be interested in
Pls help ASAP need in 10 mins
Rina8888 [55]

Answer:

Step-by-step explanation:

i think its C sorry if its wrong

8 0
3 years ago
Does anyone know the missing leg of the length?
n200080 [17]

Answer:

Hello! answer: 16

Step-by-step explanation:

These are a bit different instead your solving for B so you have to work backwords so... 20 × 20 = 400 12 × 12 = 144 400 - 144 = 256 now we just find out what multiplied by itself = 256 16 × 16 = 256 therefore b = 16 Hope that helps!

5 0
3 years ago
Read 2 more answers
Name the adjacent angles in the diagram below:​
harkovskaia [24]

Hey there!

In this picture, we have many pairs of adjacent angles:

1 and 2

2 and 4

4 and 3

3 and 1

This is because these pairs are being connected by a vertex and a side.

Hope it helps and have a great day!!!

5 0
3 years ago
A worker’s pay for one week was $312. She worked 39 hours. How much was she paid per hour?
Volgvan

To find out how much she earned hourly, all we need to do is divide 312 and 39

312 ÷ 39 = 8

Therefore, she was paid $8 per hour

Hope this helps!

8 0
3 years ago
Read 2 more answers
Help me with this math problem please, only this part because I can't seem to solve the last one, I'd like an explanation but it
jonny [76]

Why....

________________

4 0
3 years ago
Other questions:
  • I need to convert this to a scientific notation 286,300,000,000.00
    14·1 answer
  • The radius of a cone is decreasing at a constant rate of 7 inches per second, and the volume is decreasing at a rate of 948 cubi
    6·1 answer
  • Explain how u can mentally find the sum of the fractions in exercise 3 without actually performing the calculations.
    6·2 answers
  • Isabel worked 20 hours last week and earned $145.80. Nan worked 15 hours last week and earned $112.50. How much more does Nan ea
    6·2 answers
  • Which statement is a counterexample to the following conjecture?
    10·2 answers
  • Write 1= 2x2 + 5x In standard form. <br><br> What is the value of b^2 - 4ac?
    14·1 answer
  • If &lt;3 measures 123°, what is the measure of &lt;7?
    10·1 answer
  • Pls help me no one helps me
    12·2 answers
  • The two way table shows the result of a survey that asked 50 people with pet they like best. Which statements are correct?
    15·1 answer
  • Hi, can you help me answer this question please, thank you!
    8·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!