Quiz 

Functions

Let x be the digit in the ones place
    10(6 - x) + x = 3[x(6 - x)]
    60 - 10x + x = 3[6x - x2] 
    60 - 9x = 18 x - 3x2
    3x2 - 27x + 60 = 0
    x2 - 9x = -20
    x2 - 9x + 81/4 = 1/4
    x  - 9/2 = ± ½
    x = 5 or 4
 
Tenth value (1st no.) = 6 - 5 = 1
Tenth value (2nd no.) = 6 - 4 = 2
 
1st no. = 15
2nd no. = 24
 
 
Let x be speed of Ken
   
 
Speed of Ken is 16.2 km/h
Speed of John is 11.2 km/h
 
 
Let x be amt. pulled away
Pythagoras' theorem -------- a2 + b2 = c2 
Height triangle =
(12 - x)2+ (5 + x)2 = 132 
144 - 24x + x2 + 25 + 10x + x2 = 169
2x2 - 14x = 0
a = 2   b = -14   c = 0
   = 0 (n.a.) or 7
 
x is 7cm.