Question 1195961


i)
 let a positive number be {{{x}}}, 

then add four to the number and you get 

{{{x+4}}}

Next, square the resulting number, 

{{{(x+4)^2}}}

and multiply result by {{{3}}}, 

{{{3(x+4)^2}}}

Finally, divide the result by {{{2}}}, 

{{{(3(x+4)^2)/2}}}

If you’re his friend and you get a result of {{{50}}},

{{{(3(x+4)^2)/2=50}}}


ii)

now solve for {{{x}}}

{{{(3(x+4)^2)/2=50}}}

{{{3(x+4)^2=50*2}}}

{{{(x+4)^2=100}}}

{{{3(x^2 + 8x + 16)=100}}}

{{{3x^2 + 24x + 48-100=0}}}

{{{3x^2 + 24x -52=0}}}

need positive solution

{{{x = 10/sqrt(3) - 4}}}

the exact original  number is {{{ 10/sqrt(3) - 4}}}  

or approximate

{{{x =1.7735026918962582}}}