Question

If 3x - y = 7 and 2x + 5y = - 1, then the values of x and y are

• A. x = 1, y = 2
• B. x = 2, y = - 1
• C. x = 3, y = - 1
• D. x = 4, y = 2

Answer 1

The correct option is B x = 2, y = - 1

3x - y = 7 - - - - (1)
2x + 5y = - 1 - - - - (2)
Multiplying equation(1) by 2 and equation(2) by 3
$\Rightarrow$ 6x - 2y = 14 - - - - (3)
$\Rightarrow$ 6x + 15y = - 3 - - - - - (4)
Subtracting equations (4) from (3), we get
y = - 1
Substituting 'y' value in equation(1), we get
3x + 1 = 7
$x=\frac{6}{3}=2$