Question

The sum of two number is 10. when three times the first number is subtracted to 6 times the second number, the resultant number is 3. Find the numbers.

• A. $x=7$ and $y=3$
• B. $x=7$ and $y=-3$
• C. $x=-7$ and $y=3$
• D. $x=-7$ and $y=-3$

Answer 1

The correct option is A $x=7$ and $y=3$

Let the number be x and y
first equation written as
$x+y=10$ ----- (1)
second equation written as
$3x-6y=3$ ----- (2)
Multiplying equation (1) by 6 and then add the equations.
$6x+6y=60$
$3x-6y=3$
______________
$9x=63$
$x=7$
Put the value of x in equation (1)
$7+y=10$
$y=10-7$
$y=3$
Therefore the numbers are x=7 and y=3