ElectricPavlov

6 hr  x  80 km/hr = 480 km

480 km/ 5hr = 96 km/hr

Using the hint:     6 hr * 80 km/hr  =  5 hr * x  km/hr

Here is a different formula for 'speed' ......   

Add top eq to third equation to get

S + base + tennis = 695

Multiply last equation by -1 and add to this equation to get

S = 480

The tree grew   35.5 - 18 ft = 17.5 feet in 3.5 years      this averages to   17.5 ft / 3.5 yr =  5 ft/yr

perimer of rectangle                              =         perimeter of hexagon

3x+3     +  3x+3    +  x+3    +  x + 3       =        6 (2x)                           Now just solve for 'x'

 Look at the data points graphed for the 18 year olds    at  x = 10 minutes    the number of 18 year olds is  30

                                                                                        at x = 20 minutes    the number of 18 year olds  is  20

                                                                                        at x = 30 min                                                        is 60 

                                                                                          continue with the other data points and add up all of the 18 y/o's

b.   Look at x = 30  for both of the graphs and find the

'y' values and see which is greater....

Note that the triangle angle in the lower right  is equal to     180   -  (6+25x)    this plus th other two adds to 180^o

^{44    +      18x-3      +   180 - (6+25x)   = 180       Now can you solve for 'x' ?}

  area = 2   x   1/2 b h   = b h

I did    BUT there are   TWO triangles in this method of solution    2  x 1/2  = 1  

I just used the wrong base   should be   2.3511   not  4.70228      Thanx for correction !   

y = mx+ b     m = slope

y = -5/4 x + b     subst in thepoint given to calc 'b'

-3 = -5/4 (-4) + b        b = 17

y = -5/4  x   + 17

Rectagular prism portion volume  = 3 x 2 x 6    in³

Triangular volume                      == 1/2 3 x 3 x 6 in3      Add 'em up !