Solve: 7x+4y = 3 for y

Question

Can you please show me how to do the problem and also check it? My professor asks for a check on ALL problems and that is the hardest part for this one. Thank you in advance :)

Answer 1

7x+ 4y = 3

4y = 3-7x

y = (3-7x)/4

to check the answer, plug it back into the original equation

7x +4y =3

7x + 4(3-7x)/4 = 3 the 4's cancel 4(3-7x)/4 = 3-7x

7x + 3-7x = 3 the 7x's cancel 7x-7x = 0

3 = 3 the answer works

Answer 2

7x + 4y = 3

7x - 7x + 4y = 3 - 7x [ Subtract 7x from both sides ]

0 + 4y = 3 - 7x [ + 7x - 7x = 0 ]

4y = 3 - 7x

(4y) / 4 = ( 3 - 7x) / 4 [ divide both sides by 4 ]

y = (3 - 7x) / 4