The standard form of a linear equation in $$n$$ unknowns $$x_1,x_2,\dots ,x_n$$ is $$a_1x_1+a_2x_2+\dots +a_nx_n=b,$$ where $$a_1,a_2,\dots ,a_n$$ and $$b$$ are constants. Here constants mean some real numbers (these constants may come from any number field). A collection of one or more linear equations of same variables is called...

1) The H.C.F. of $$\frac{9}{4},\frac{3}{20},\frac{9}{10} and \frac{15}{16}$$ is: A) $$\frac{3}{80}$$ B) $$\frac{3}{2}$$ C) $$\frac{1}{40}$$ D) $$\frac{45}{2}$$   2) The L.C.M. of $$\frac{2}{3},\frac{3}{20},\frac{9}{10} and \frac{15}{16}$$ is: A) $$\frac{3}{80}$$ B) $$\frac{3}{2}$$ C) $$\frac{1}{15}$$ D) $$\frac{45}{2}$$   3) The H.C.F. of 1.26, 1.155, 0.21 and 0.315 is: A) 0.05 B) 0.105 C) 1.05 D) 0.03...