SOLUTION: A two digit question is such that it's digit is greater than its unit by 5,if the number is 14 less than 3 times the product of its digit,find the number

Algebra ->  Customizable Word Problem Solvers  -> Numbers -> SOLUTION: A two digit question is such that it's digit is greater than its unit by 5,if the number is 14 less than 3 times the product of its digit,find the number      Log On

Ad: Over 600 Algebra Word Problems at edhelper.com


    

Question 1107739: A two digit question is such that it's digit is greater than its unit by 5,if the number is 14 less than 3 times the product of its digit,find the number
Answer by ikleyn(52794) About Me  (Show Source):
You can put this solution on YOUR website!
.
A two digit highlight%28cross%28question%29%29 number is such that highlight%28cross%28it%29%29'highlight%28cross%28s%29%29 its highlight%28tens%29 digit is greater than its unit highlight%28digit%29 by 5.
If the number is 14 less than 3 times the product of its highlight%28cross%28digit%29%29 digits, find the number
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

        Is it so difficult for you to write the post accurately ?


Let us present the unknown number N in decimal form via its "tens" digit "t"  and  "ones" digit "u"  N = 10*t + u.


Then the condition says

t = u + 5                   (1)
10*t + u = 3*t*u - 14.      (2)


It is your system of equations to solve.

From (1), substitute the expression for "t" into equation (2). You will get

10*(u+5) + u = 3*(u+5)*u - 14,

10u + 50 + u = 3u^2 + 15u - 14,

3u^2 + 4u - 64 = 0,

u%5B1%2C2%5D = %28-4+%2B-+sqrt%284%5E2+-+4%2A3%2A%28-64%29%29%29%2F%282%2A3%29 = %28-4+%2B-+28%29%2F6.


The only integer positive solution is u = 4.

Then   t = u+5 = 9.


The number is  94.