Question 826650

let two numbers be {{{x}}} and {{{y}}}
if the  product of two whole numbers is {{{90}}}, then we have

{{{xy=90}}}........eq.1


if one number (let it be {{{x}}}) is {{{2.5}}} times as great as the other (let it be {{{y}}}), then we have

{{{x=2.5*y}}}..........eq.2

now solve the system: 

{{{xy=90}}}........eq.1
{{{x=2.5*y}}}..........eq.2
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{{{xy=90}}}........eq.1.............substitute {{{x}}} from eq.2

{{{2.5y*y=90}}}........solve for {{{y}}}

{{{y^2=90/2.5}}}

{{{y^2=36}}}

{{{y=sqrt(36)}}}

{{{y=6}}} or {{{y=-6}}}

now find {{{x}}}

{{{x=2.5*y}}}=> {{{x=2.5*6}}}=> {{{x=15}}}

or

{{{x=2.5*y}}}=> {{{x=2.5*(-6)}}}=>{{{x=-15}}}


so, your numbers are

{{{x=15}}} and {{{y=6}}}

or

{{{x=-15}}} and {{{y=-6}}}