1.25(x-4)=5+25 solve show all work and check

Answer 1

Hi Sarah,

when we work with algebra we also manipulate numbers. the way we manipulate numbers can make the problem easier or can make it complicated. so before getting busy multiplying pause and think what is the best way to manipulate this problem. Also ask yourself what is my target?

the target is to isolate x on one side and numbers on the other side of the equation.

how can we do that? simply by manipulating the numbers in a clever way to rearrange the equation.

Now look at the equation and think what can I do?

1.25(x-4) = 5+25

remember adding and multiplying makes numbers bigger while dividing makes them smaller. smaller means easier and manageable.

1.25(x-4) = 5+25

looking at all numbers in both sides I noticed 5 as a common factor. dividing both sides by 5 will make the numbers smaller.

notice that 1.25 is multiplied by the whole bracket (x-4), so dividing 1.25 by 5 is all we need on the left hand side and the bracket stays the same

0.25 (x-4) = 1+ 5

now the right hand side adds to a small number '6'

0.25 (x-4) = 6

the left hand side has our variable x between brackets where the bracket is multiplied by 0.25, there is two steps to isolate x, we need to get rid of the 0.25 and we need to get rid of the 4 inside the bracket.

if we use the fraction notation of the 0.25 it will look better as it simply translates to 1/4

(1/4) (x-4) = 6

now getting rid of the (1/4) should be easy, just multiply both sides by 4

4*(1/4)(x-4) = 4*6

(x-4)=24

REMEMBER when you have an equality, if you multiply one side by a number, multiply the other side by the same number, this way the two sides stay equal.

last step, keep your target in mind, why are we doing this? we are trying to isolate x in one side and all other numbers on the other side.

to have only x on the left hand side we add 4, this way it cancels out the subtracted 4 and we get our x

x-4 +4 = 24 +4

did you notice the addition of 4 on the right hand side? excellent: we had to add 4 to both sides so both sides are equal.

reduce the equation and we get:

x = 28

If you liked my answer: give me a 5 star review ;)