Question 1121638

let's Maggie’s age be {{{x}}} and her brother's age {{{y}}}

if Maggie’s brother is {{{7}}} years {{{younger}}} than {{{four}}}{{{ times}}} her age, we have

{{{y=4x-7}}}....eq.1

if the sum of their ages is {{{68}}}, we have

{{{x+y=68}}}.....eq.2


substitute {{{y}}} from eq.1 in eq.2

{{{x+4x-7=68}}}

{{{5x=68+7}}}

{{{5x=75}}}

{{{x=75/5}}}

{{{x=15}}}

so, Maddie is {{{15}}} years old

and her brother is:

{{{y=4x-7}}}=>{{{y=4*15-7}}}=>{{{y=60-7}}}=>{{{y=53}}}