Question 326287
the vertically opposite angles when 2 lines intersect are equal
{{{5x=7x-12}}}
add-7x to both sides
{{{5x-7x=7x-7x-12}}}
{{{-2x=-12}}}
divide by -2
{{{-2x/-2=(-12)/-2}}}
{{{x=6}}}
If x= 6 , 5x= 30
to check
7x-12=7*6-12
=30
The angles are 30 deg.