Question 262205: I need help with the equation 3(4x-9)=x+100. So far I have done two steps and then i am completely lost? My first step I got 12x-27=x+100, then the second step I got 12x=x+127, now I cant figure out how do I divided the 12 with the x or the 127?
Answer by Theo(13342)   (Show Source):
You can put this solution on YOUR website! your equation is:
3*(4*x-9) = x+100
simplify to get:
12*x - 27 = x + 100
so far you did good.
add 27 to both sides of this equation to get:
12*x = x + 100 + 27
you simplified this to get:
12*x = x + 127
so far you still did good.
you needed to get all the x's on one side of the equation.
you do that by subtracting x from both sides of the equation to get:
12*x - x = 127
simplify that to get:
11*x = 127
now you divide both sides of the equation by 11 to get:
x = 127 / 11 = 11.54545454
that should be your answer.
you confirm by substituting for x in the original equation.
original equation is:
3*(4*x-9) = x+100
substitute 11.54545454 for x to get:
3*(4*11.54545454 - 9) = 11.54545454 + 100
simplify to get:
3 * (37.18181818) = 111.54545454
simplify further to get:
111.54545454 = 111.54545454 confirming that the value calculated for x is good.
the numbers displayed on the calculator are usually rounded to the nearest 8 decimal places or thereabouts.
I used the internally stored numbers which are carried out to more digits than can be displayed.
If you just use the 8 or so decimal places displayed, your answer will be very close.
If you then round to the nearest 1 or 2 decimal places, your answer should be right on.
|
|
|
