Question

(2)^7x-7 = 1 then find the value of ‘x’

Answer 1

Step-by-step explanation:

The best way to solve these is to try to move the numbers where all the numbers are on one side, and the unknown X is on the other side.

So we will start by moving the -7. To do this, we need to do something to both sides, so that the equation remains true. You cannot just remove stuff from one side, you need to remove or add or multiply both sides.

So what is the best way to remove the -7? By adding a 7 to both sides:

7x-7 = 7 (what we have)

7x-7+7 = 7+7 (adding 7 to both sides of the equal sign)

7x = 14 (-7 +7 equals 0 so we only have 7x left)

We removed one number, lets go for the other. Remember where I said we can do all kinds of things to both sides, so how can I get from 7x, or 7 times x to just x? well x is the same as 1 times x. If it helps:

7x = 7*x = 7 * (1*x)

All of these are the same, but we never write 1*x as 1*x, only as x, and this is what will allow us to get rid of the 7. How to make a 7 into an 1? We could subtract, 7–6=1 right? Well yes, but you cannot subtract from a member of a multiplication just like that, because you want to.

Instead, any number divided by itself will give you 1. 13/13=1 and 2732819/2732819=1

So let’s divide it by 7 and see where we go. Remember though, that what we do in one side, we must do to the other.

7x=14 (what we have)

7x/7 = 14/7 (divide both sides by 7)

1x = 2 or as we typically write it: x=2