Answer:
17.8 cm
Step-by-step explanation:
In the 17 hours between heights of 18.6 cm and 15.2 cm, the candle lost 3.4 cm in height. That is, the height decreased at the rate of ...
(-3.4 cm)/(17 h) = -0.2 cm/h
In the 4 hours between 12 hours and 16 hours of burning time, the candle will have changed its height by (4 h)(-0.2 cm/h) = -0.8 cm.
The height at 16 hours of burning is then 18.6 cm -0.8 cm = 17.8 cm.
2x + 6y = 12
2x - 2x + 6y = 12 - 2x
6y = 12 - 2x
6y/6 = 12/6 - 2x/6
Y = 2 - 2/6 X
Y = 2 - 1/3 X or
Y = -1/3 X + 2.
Answer:
10 and 15
Step-by-step explanation:
Let 'x' and 'y' are the numbers we need to find.
x + y = 25 (two numbers whose sum is 25)
(1/x) + (1/y) = 1/6 (the sum of whose reciprocals is 1/6)
The solutions of the this system of equations are the numbers we need to find.
x = 25 - y
1/(25 - y) + 1/y = 1/6 multiply both sides by 6(25-y)y
6y + 6(25-y) = (25-y)y
6y + 150 - 6y = 25y - (y^2)
y^2 - 25y + 150 = 0 quadratic equation has 2 solutions
y1 = 15
y2 = 10
Thus we have
:
First solution: for y = 15, x = 25 - 15 = 10
Second solution: for y = 10, x = 25 - 10 = 15
The first and the second solution are in fact the same one solution we are looking for: the two numbers are 10 and 15 (since the combination 10 and 15 is the same as 15 and 10).
Answer:
2 nd one
Step-by-step explanation:
