Question 159296
"average of two numbers is 7" --> {{{(x+y)/2=7}}}



"three times one of the numbers is one half the other number" ---> {{{3x=(1/2)y}}}



{{{3x=(1/2)y}}} Start with the second equation



{{{6x=y}}} Multiply both sides by 2



{{{y=6x}}} Rearrange the equation



{{{(x+y)/2=7}}} Move onto the first equation



{{{(x+6x)/2=7}}} Plug in {{{y=6x}}}



{{{(7x)/2=7}}} Add



{{{7x=14}}} Multiply both sides by 2



{{{x=2}}} Divide both sides by 7



So the first number is 2 and the second number is {{{y=6(2)=12}}}