Another problem I need help with

Question

anonymous · Answer

@ijlal

anonymous · Answer

attachment

ijlal · Answer

@unknownshadow  lets get on with question 16 first :) do you know the standard equation of a line?

ijlal · Answer

$$y-y_{1}=m(x-x _{1})$$
@unknownshadow  do you know this equation?

anonymous · Answer

Yes I think so. @ijlal

ijlal · Answer

so lets start with the purple line :) we can see that the purple line cuts the y-axis at -3 so the point is (0,-3) right?

anonymous · Answer

Yes.. I never fully understood graphs. @ijlal

ijlal · Answer

@unknownshadow  same here but took lots of practice you will learn too :) that's what i am trying to teach you :) i can straight away give you answers but its better to make you understand and you approach the answer on your own :) 
So till here you understood that point is (0,-3)?

anonymous · Answer

Thank you (: and yes @ijlal

ijlal · Answer

so to find the equation of a line we need it's slope and to find the slope we need two points that lie on the line so we got our first point (0,-3) lets take (4,5) as our next point the point should lie on the line and the formula of slope is |dw:1462980026791:dw|