A= 1/4E
B= 4E
C= E-4
D= E+4
A+B+C+D=100
25/4E=100
hence, E=16
The cube root of 81 is 4.32674871092
Let x, represent the number of minutes and y represents the number of gallons of water in the tub, then the ordered pairs (2, 30) and (5, 12) satisfies the equation.
Therefore the equation is given by: (y - 30)/(x - 2) = (12 - 30)/(5 - 2)
(y - 30)/(x - 2) = -18/3 x = -6
y - 30 = -6(x - 2) = -6x + 12
y = -6x + 42
Required equation is y + 6x = 42.
Find the slope of the line connecting (1990,435000) and (2005,482300):
482300-435000 47300
m = ----------------------- = ---------------- = 3153/yr (approx)
2005 - 1990 15 yr
Use the point-slope formula to find the equation of this str. line:
y-435000 = (3153/yr)(x-1990)
The year 2020 is 30 years after 1990. Thus, the expected pop in 2020 is
given by y-435000 = 3153(30) = 94590, so that y = 529590.