Plz help me with this questions and show working out thanks

 The steps and answers to the first two are below but you need to understand slope  = change in y / change in x  = y2 - y1/ x2 - x1  

And you need to understand  y = mx + c  

m= slope   c is y intercept

Substitute either point given  - only use one as the x and y  and find c

Step-by-step explanation:

1.      You need to follow the steps -

          the point is given as  (2,5)  = (x,y)  

So what this means is  x =2 and y =5

Simple substitutions is the step  5   = 3 x 2 + c

                                                     5 = 6 + c  or easier to see is  c + 6 =5

subtract 6 from both sides   c +  6   =  5

                                                    -6      -6

                                              c           =  -1

2.

 x1,y1           x2,y2

( 3,2)   and (5,6) are two points on the line  

you already calculate the slope which is   m = noy2-y1/x2-x1 = 6-2/5-3 = 4/2 = 2

Remember y= mx + c

                   y = 2 x + c

now substitute in (3,2) which is (x1, y1) into the x and y in your equation

                  2  = 2 (3)  + c

                  2 = 6 + c

 subtract 6 from both sides

                  -4 = c

Now you should use this and do your last question  yourself

since the airplane is moving with constant speed then the distance travelled can be calculated by x=u*t

in km/h would be:

x=640*3.5=2.240 km

in m/s would be:

u=640 km/h= 640.000 m/h =640.000/ 3600 m/s =177.8 m/s

t= 3.5 h= 3.5 * 3600 s=12.600 s

then x=u*t= 177.8*12.600= 2.240.280 m

step-by-step explanation:

this is not a question