184,438 views
1 vote
1 vote
The sum of two numbers is 3. Their difference is 13. Find the numbers.

User Peter Karlsson
by
2.5k points

2 Answers

12 votes
12 votes


\text{Let the two numbers be x and y}\\\\x+y=3~~~.....(i)\\\\x-y=13~~~.....(ii)\\\\\text{(i)+(ii):}\\\\x+y+x-y = 3+13\\\\\implies 2x = 16 \\\\\implies x = \frac{16}2 = 8\\\\\text{(ii)-(i):}\\\\x-y-x-y=13-3\\\\\implies -2y=10\\\\\implies y= -5\\\\\text{Hence the numbers are }~8~\text{and}~ -5

User Nknight
by
3.5k points
12 votes
12 votes

Answer:

The numbers are

5

and

8

Explanation:

We know:

m

n

=

3

And we know:

m

+

n

=

13

Next, solve the first equation for

m

:

m

n

+

n

=

3

+

n

m

0

=

3

+

n

m

=

3

+

n

Then, substitute

3

+

n

for

m

in the second equation and solve for

n

:

m

+

n

=

13

becomes:

(

3

+

n

)

+

n

=

13

3

+

2

n

=

13

3

+

3

+

2

n

=

3

+

13

0

+

2

n

=

10

2

n

=

10

2

n

2

=

10

2

2

n

2

=

5

n

=

5

Now, substitute

5

for

n

in the solution to the first equation and calculate

m

:

m

=

3

+

n

becomes:

m

=

3

+

5

m

=

8

The solution is:

n

=

5

and

m

=

8

User Sai Kumar Reddy
by
3.1k points