we have
[tex]4.2x-1.4y=2.1[/tex]
Solve for y--------> clear the variable y
[tex]4.2x-1.4y=2.1[/tex]
Subtract from both sides [tex]4.2x[/tex]
[tex]4.2x-1.4y-4.2x=2.1-4.2x[/tex]
[tex]-1.4y=2.1-4.2x[/tex]
Divide both sides by [tex]-1.4[/tex]
[tex]y=(2.1-4.2x)/(-1.4)[/tex]
[tex]y=-\frac{2.1}{1.4} +\frac{4.2x}{1.4}\\ \\y= -1.5+3x\\ \\y=3x-1.5[/tex]
therefore
the answer is
[tex]y=3x-1.5[/tex]
