Heya !
Given expression -

Subtracting 25 both sides ,

Dividing by 3 on both sides ,

Therefore ,
Answer:
x = 1 because when you multiply negative 2 by negative six you get twelve. when you multiply positive one by negative six you get negative six.
For questions 4 and 5, use laws of complementary and supplementary angles to find values of x. I'm not too sure about what question 10 is asking.
Hope I helped :)