The correct answer is the <u>left</u><u> </u><u>graph</u>.
In intercept form, the plane that has these intercepts is ...
... x/(x-intercept) + y/(y-intercept) + z/(z-intercept) = 1
... x/1 + y/(-1) + z/2 = 1
... 2x -2y +z = 2 . . . . . in standard form
The answer is b because the slope is 2 and the y intercept is 9
if an ordered pair is a solution, it should satisfy the equation.
see the first option
, if you put $x=4$ and $y=12$
you'll get $12=12$ which is true.
now the last option, $y=8-x$ put $x=4$ and $y=12$
$12=8-4\implies 12\ne4$ thus it is not a solution.
So option 4 is correct
The adult tickets cost $5 and the child tickets cost $2
Monday
5 x ($2) + 3 x ($5) = $25
Tuesday
4 x ($2) + 4 x ($5) = $28