SOLUTION: I posted this problem and someone was able to proved the algebraic equation for it, but unfortunantly, I still do not understand how to solve it: "I am thinking of three consecu

Question 175028: I posted this problem and someone was able to proved the algebraic equation for it, but unfortunantly, I still do not understand how to solve it:
"I am thinking of three consecutive numbers. If I multiply the first with the second and then subtract three times the third, the result is 57. What are the numbers?"
The equation given was x(x+1) - 3.(x+2)=57
Can someone please help me to actually solve this? Thanks
Found 3 solutions by scott8148, actuary, jojo14344:
Answer by scott8148(6628)   (Show Source): You can put this solution on YOUR website!
distributing gives __ x^2+x-3x-6=57

subtracting 57 __ x^2-2x-63=0

factoring __ (x-9)(x+7)=0

so x equals 9 or -7

which makes the numbers 9, 10, 11 or -7, -6, -5
Answer by actuary(112)   (Show Source): You can put this solution on YOUR website!
Let me give a try.
Let x be the first number, x+2 is the second number and x+3 is the third number.
x*(x+1)-3*(x+2)=57
Simplify the equation.
x^2+x-3*x-6=57
So x^2-2*x-63=0
WE have a quadratic equation so by the quadratic formula
x=-[-(-2)+/-Sqrt(-2^2-4*1*(-63)]/2*1
x=2+/-Sqrt[4+252]/2=2+/-Sqrt[256]/2
x=(2+/-16)/2
There for x =18/2=9
or x = -7
So the the three consectutive numbers are 9,10,11
or -7,-6,-5
I hope that this helps.
Answer by jojo14344(1513)   (Show Source): You can put this solution on YOUR website!

------------------------> working eqn
where the numbers----->
Continuing:
, distribute,expand, & put all terms to the left

By QUadratic, where---->

2 values:
----->,&
--->,&
Check by going back to the working eqn:

, good

, good
Thank you,
Jojo
RELATED QUESTIONS
Hi Tutors: I really appreciate your help. However, I have not been able to get help... (answered by prince_abubu)
Hello, I am a little confused on how to solve this algebraic equation. I see someone... (answered by sofiyac)
Twenty minutes after Melissa�s older sister left home for band practice, Melissa saw... (answered by josmiceli)
I actually attempted the examples in my book but still do not grasp the concept if I can... (answered by stanbon,ankor@dixie-net.com,jim_thompson5910)
Trying to assist 13 yr old son.. Just when I think there wont be a problem helping... (answered by solver91311)
Sorry, I forgot to put consecutive in the problem I last posted. Here it is again in... (answered by scott8148)
I am a parent I want to help my child but i don't know how to do this. I'm not asking for (answered by Alan3354,josmiceli,ankor@dixie-net.com)
Hi Everyone, I'm not sure if I posted this question in the Correct category but I am... (answered by ankor@dixie-net.com)
Please Help. I have a textbook and it takes me through the steps on what I need to do,... (answered by Fombitz)