Question

If twice the number of x and 7 is added to the number of y, the sum is 18. But if thrice the number of x is subtracted to the number of y, the difference is 4. Find the number of x and y.

• A. $x=-2;y=2$
• B. $x=2;y=-2$
• C. $x=2;y=2$
• D. $x=-2;y=-2$

Answer 1

The correct option is C $x=2;y=2$

As per the given statement form equations,
$7x+2y=18$ ----- (1)
$3x-y=4$ ----- (2)
Multiplying the equation (2) by 2 and then subtract the equations:
$7x+2y=18$
$6x-2y=8$
____________
$13x=26$
$x=\frac{26}{13}$
$x=2$
Substitute the value of x in equation (2),
$3x-y=4$
$3\left(2\right)-y=4$
$6-4=y$
$y=2$
Therefore, the number of x and y is 2 and 2