Question 124679
Two numbers, so one of them is x and the other is y.

Their difference is 7, so {{{x-y=7}}}


The second, y, is, meaning equals, 4 less than two times the first.  2 times the first is {{{2x}}}, 4 less than that is {{{2x -4}}}, so {{{y = 2x-4}}}, or in standard form, {{{2x-y=4}}}



{{{x-y=7}}}
{{{2x-y=4}}}


Multiply the first equation by -1:


{{{-x+y=-7}}}


Then add the second equation to it


{{{x+0y=-3}}}


{{{x=-3}}}


Substitute into the first equation:

{{{-3-y=7}}}


{{{-y=10}}}


{{{y=-10}}}