Question

Solve 12x + 4y = 20 for y.

A. y=-3x+ 20
B. y = -12x+ 20
C. y= 12x+ 5
D. y=-3x+ 5

Answer 1

`\boxed{ \bold{ \huge{ \boxed{ \sf{y = - 3x + 5}}}}}`

Option D is the correct option.

Explanation:

`\sf{12x + 4y = 20}`

Move 12x to right hand side and change it's sign

⇒
`\sf{4y = - 12x + 20}`

Divide both sides of the equation by 4

⇒
`\sf{ (4y)/(y) = ( - 12x + 20)/(4) }`

⇒
`\sf{y = ( - 12x)/(4) + (20)/(4) }`

Divide -12x by 4 . Also divide 20 by 4

⇒
`\sf{y = - 3x + 5}`

Hope I helped!

Best regards!! :D

Answer 2

D. y= -3x+ 5

Explanation:

`12x + 4y = 20`

Move 12x to the right and change its sign

`4y =20-12x`

Divide through by 4

`(4y)/(4) = (20)/(4) -(12x)/(4) \\\\Simplify\\y = 5-3x\\y =-3x+5`