Answer:
30
Step-by-step explanation:
x=13
because they're alternate adjacent angles:
5x=78-x
6x=78
5x-3=42. To solve you add three to both sides making the equation 5x=45. Then you divide both sides by five, and you get 9 as your answer.
(i) (x+3)(x-4)=0
(ii) (2x-3)(x-1) =0