Answer:
see explanation
Step-by-step explanation:
note when x = - 3
(- 3)³ + 2(- 3)² + 4(- 3) + 21 = - 27 + 18 - 12 + 21 = 0
hence x = - 3 is a zero and (x + 3) is a factor and dividing gives
= (x + 3)(x² - x + 7)
For zeros equate to zero
(x + 3)(x² - x + 7) = 0
equate each factor to zero and solve for x
x + 3 = 0 ⇒ x = - 3
x² - x + 7 = 0 ← solve using quadratic formula
x = (1 ± 
) / 2 = (1 ± 3i
) / 2
x = 
± 
zeros are x = - 3, x = ±
Answer:
10.1%
Step-by-step explanation:
The first thing we should do is calculate the total volume of the solution when mixing them would be:
0.7 + 0.3 = 1
Now, we have that the resulting concentration (x) would be equal to the sum of the multiplications between the volumes and the concentrations to be mixed, as follows:
x * 1 = 0.7 * 0.05 + 0.3 * 0.22
x = 0.035 + 0.066
x = 0.101
That is, the concentration of the resulting mixture would be 10.1% (0.101 * 100)
Result, Rachel can be certain that the temperature is suitable for her cake.
Answer:
14.25 hours
Step-by-step explanation:
Four tires = 3/4 of an hour
=> 1 car = 3/4 of an hour
=> 19 cars = ?
=> If 1 = 3/4
=> 19 = 3/4 x 19
=> 3/4 x 19
=> 57/4
=> 14.25 hours
So, it would take 14.25 hours for 19 car's tires to be changed.
