It means the lens will magnify the object by a factor of four
Yes if you mean: y-4x = 3
Normal rules mean x takes precedent over +, so you get 24 +4x. But if you mean 12(2+4x) then it's 24+48x
-3
2
5
Do you mean 4x-3y = 12 then it is at (3, 0)
If you mean: 3x-(2x+4x-6) then 3x-2x-4x+6 simplifies to 6-3x
I assume you mean y = 4x If so, then it is 4.
If you mean: 6x-4x-2+11x then it can be simplified to 13x-2
If you mean: 4x+8y = 12 then the y intercept is 12
If you mean: 4x -2 = 86 then the value of x is 22 when solved
If you mean: -4x -5y = 20 then y = -0.8x -4