X + y = 2 —> y = 2 - x
insert to first equation
2-x=x^2-3x-6
x^2 - 3x - 6 - 2 + x = 0
x^2 - 2x - 8 = 0
(x-4)(x+2) = 0
x = 4 or x = -2
The three refers to 3 ten thousands. or 3 x 10,000.
Answer:
≈ 20.8 ft
Step-by-step explanation:
A right triangle is formed between the wall, the ground and the ladder.
The ladder is the hypotenuse , the wall and ground are the legs.
let h be the height of the wall, then using Pythagoras' identity
h² + 33² = 39²
h² + 1089 = 1521 ( subtract 1089 from both sides )
h² = 432 ( take the square root of both sides )
h = 
≈ 20.8 ft ( to the nearest tenth )
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.
