1. solving
y=-7x+5
x=-7y+5 (change y to x and x to y)
x-5=-7y (transpost 5 and change its sign)
x-5/-7=-7y/-7 (divide each to -7 so that "y" will remain)
final answer: y=x-5/-7
2. do the same like number 1
y=3x^2+2
x=3y^2+2
x-2=3y^2
x-2/3=3y^2/3
y^2=x-2/3
(squareroot of y^2) = (squareroot of x-2/3) [add square root to cut out the squared]
final answer = y= + or - (square root of x-2/3)
3. y=6x+1/2
x=6y+1/2
x-1/2=6y
(2)(x-1/2) = (6y)(2) [multiply each by two so that 2 in 1/2 will be cut out]
x-1 = 12y
x-1/12=12y/12
final answer: y=x-1/12
hope it helps :)