Use the working backword method to find the solution of the equation
4y-1=7

You'd do plus 1 cause that the backward way then add one to seven also and you'll have 4y=8 then divide 4 to each side so y=2

4y-1=7

Basiclly, you need to add one to the other side and subtract one from the original side so there is just 4y there.

That leaves you with 4y=8

Then divide both sides by four so there is no number by y. 8/4 is 2.
y=2.   

And when you check your answer, 4(2)-1=7
                                                          8-1=7
                                                             7=7
                                                  The answer is true.

Answer: v= lwhstep by step explanation: length x width x heightl = 12kmw = 6kmh = 6km12 x 6 = 7272 x 6 = 432therefore your answer would be c) 432 km^3