I know that the value of x=-5 but how do i show the working out??!?!?
add 3x to both sides of the = 5 - 3x + 3x = 20 + 3x 5 = 20 + 3x
take 20 away from both sides of = 5 - 20 = 20 + 3x - 20 -15 = 3x
divide both sides by 3
-5 = x x = -5
i.e. loads of different ways that are basically doing the same thing mathematically to both sides of the equation until you get x's on one side and a number on the other