vertical angles are always congruent so the E & F have to have the same end result
therefore we have to find a single x value that makes E & F equal each other
okay so we can set the equations to equal each other and solve for x
so:
9x + 12 = 3x + 24
we need to get all the x terms to one side so let's subtract 12 from both sides
now we have
9x = 3x + 12
now let's subtract 3x from both sides to get
6x = 12
we can solve for x like normal now
x = 2
now to check this and see if it is accurate we plug in 2 for x in both equations
E = 9(2) + 12
E = 30
F = 3(2) + 24
F = 30
because they both got the same answer, we know that x = 2 is the right answer