For simultaneous equations in variables \(x\) and \(y\), \(D_x = 49\), \(D_y = -63\), \(D = 7\), then what is the value of \(x\) ?
Q.1 (A)(i) For simultaneous equations in variables \(x\) and \(y\), \(D_x = 49\), \(D_y = -63\), \(D = 7\), then what is the value of \(x\) ?
A. 7
B. –7
C. \(\dfrac{1}{7}\)
D. \(-\dfrac{1}{7}\)