Question

4.2x - 1.4y = 2.1 solve for y

Answer 1

4.2x-1.4y=2.1
-4.2x        -4.2x
____________
  1.4y = -2.1x
(10)            (10)
_____________
 y= - 3x/2

Answer 2

we have

$4.2x-1.4y=2.1$

Solve for y------> that means isolate the variable y

Subtract $4.2x$ both sides

$4.2x-1.4y-4.2x=2.1-4.2x$

$-1.4y=2.1-4.2x$

Divide by $-1.4$ both sides

$y=-\frac{2.1}{1.4} +\frac{4.2}{1.4}x \\ \\y=3x-1.5$

therefore

the answer is

$y=3x-1.5$