Let 11x + 15y + 23 = 0 be equation (1)
And 7x - 2y - 20 = 0 be equation (2)
Multiply equation (1) by 2:
22x + 30y + 46 = 0
Multiply equation (2) by 15:
105x - 30y - 300 = 0
Add equations (1) and (2):
22x + 105x + 30y - 30y + 46 - 300 = 0
127x - 254 = 0
127x = 254
x = 254/127
[x = 2]
Substitute x = 2 in equation (1) to find y:
11(2) + 15y + 23 = 0
22 + 15y + 23 = 0
15y + 45 = 0
15y = -45
y = -45/15
y = -3
Therefore, x = 2 and y = -3.
Answer:
El uranio es el combustible más utilizado para producir energía nuclear. Eso es porque los átomos de uranio se separan con relativa facilidad. El uranio también es un elemento muy común que se encuentra en las rocas de todo el mundo.
Step-by-step explanation:
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Answer:
Step-by-step explanation:
Air pressure is measured in pascals. For a professional American football game, the ball should be inflated to about 90,000 pascals. Scientists studied the effects of air temperature on the pressure inside American footballs by taking these steps:
1. Prepare 100 footballs.
2. Measure each football's air pressure.
3. Divide footballs into 10 groups.
4. Place the groups in different lockers cooled to different air temperatures.
5. After 12 hours, remove the footballs from lockers.
6. Measure each football’s pressure again.
7. Compare the new pressures to the starting pressures.
What two terms best describe the variable "air pressure inside the football" in this experiment?
independent, qualitative
independent, quantitative
dependent, qualitative
dependent, quantitative
Answer:
Option B - 90 students at random during lunch
Step-by-step
An unbiased sample is defined as:
A sample is an unbiased sample if every individual or the element in the population has an equal chance of being selected.
Based on this, we can eliminate:
Option A) - It prevents non-eighth-graders of the school from being represented.
Option C) - Students in a hallway might take a particular class together/may be of the same grade. This gives them an unfair advantage.
Option D) - All students who are not in chorus are not represented in this set.
