Question

The sum of two numbers is 20 and the difference is 12. What are the numbers?

Answer 1

Answer:

1) A system of two linear equations to represent this problem

x+y=20 and x-y=12

2) The numbers are x=16 and y=4

Step-by-step explanation:

Let x and y be the two numbers

Given that the sum of the two numbers is 20

That is $x+y=20\hfill (1)$

and the difference is 12

That is $x-y=12\hfill (2)$

1) A system of two linear equations to represent this problem

$x+y=20\hfill (1)$

$x-y=12\hfill (2)$

2). Noe Solve the system to find the 2 numbers:

Adding the equations (1) and (2) we get

$x+y=20$

$x-y=12$

_____________

2x=32

$x=\frac{32}{2}$

Therfore x=16

Now substitute x=16 in equation (1) we get

$16+y=20$

$y=20-16$

Therefore y=4

Therefore the numbers are x=16 and y=4