This question was submitted by Nonhle
Remember that when you are solving for x in a linear equation (that means that x does not have any exponents) you need to take all the numbers to one side and all the x’s to the other side.
For example: Solve for x:
4x + 5 = 7 – 2(-2x – 5)
First multiply out the bracket on the right:
|4x + 5 = 7 + 4x + 10||Remember that a negative times a negative is a positive.|
when we take the x’s to the one side we notice that they cancel:
4x -4x + 5 = 17
This means that there is no real solution for x, or x does not exist. The two sides of the equation are not equal to each other.
If we changed the equation to say:
4x + 5 = 7 + 2(-2x – 5)
Then we could solve for x (Remember you cant change the equation in the exam – try to answer the question given to you. If the teacher realises that the question is wrong when she/he starts to mark it – you will get the marks anyway).
4x + 5 = 7 -4x – 10
|4x + 4x = 7 – 10 -5||Take the x’s to one side and the numbers (or constants) to the other side.|
|8x = -8||Now divide both sides by the number attached to the x|
|x = -1||Now you have your final answer|