Question

A number doubled and added to a second number is equal to 20. Four times the first number minus the second number is equal to 10. Find the two numbers.

Answer 1

let us suppose the first no. is x and second no is y

According to 1st condition

x+y=20.................................. .............1

4x-y=10...... .. . ........... . ............... ..2

add both

x=6

put x=6 in 1

6+y=20

y= 20 -6

y=6

3,6

Answer 2

Answer:the first number is 5

The second number is 10

Explanation:

Let x represent the first number.

Let y represent the second number.

A number doubled and added to a second number is equal to 20. This means that

2x + y = 20 - - - - - - - - - -1

Four times the first number minus the second number is equal to 10. This means that

4x - y = 10 - - - - - - - - - - -2

We would eliminate y by adding equation 1 and equation 2. It becomes

6x = 30

x = 30/6 = 5

Substituting x = 5 into 2x + y = 20, it becomes

2 × 5 + y = 20

10 + y = 20

y = 20 - 10 = 10