Answer:
Eric's expression is :
and Andrea's is :
In Eric's expression, 20 represents the initial amount of substance with which he has started the experiment. 
is the amount of substance left after each time period (in this case, each week).The variable w in this case represents the number of weeks.
Andrea's expression can be written as :
The one outside of parentheses represents the initial amount of the substance. The one inside of parentheses represents 100% of the original amount of the substance. 0.5 represents the 50% of the substance that is lost each time period. The variable w in this case represents the number of weeks.
Answer: y = -2x -2
Step-by-step explanation:
Making y the subject of the formula
Subtract 4 from both sides
⇒ y = -2 ( x - 1 ) - 4
y = -2x + 2 -4
y = -2x -2
Answer:
The time taken for the projectile to reach the given height is 1.2 s.
Step-by-step explanation:
Given;
height of travel, h = 25 ft
initial velocity of the projectile, u = 15 ft/s
The time taken for the projectile to travel a height of 25 ft is given by the following kinematic equation;
h = ut + ¹/₂gt²
25 = 15t + ¹/₂(9.8)t²
25 = 15t + 4.9t²
4.9t² + 15t - 25 = 0
solving the quadratic equation, we will have the following solution of t;
t = 1.2 s
Therefore, the time taken for the projectile to reach the given height is 1.2 s.
Answer:
r = 6 cm
Step-by-step explanation:
The volume of a sphere is 288 pi cm tripled . Find the lenght of a radius of a SPHERE.What is the answer and how did you do it?
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The volume of a sphere of radius r is:
V+=+4%2Api%2Ar%5E3%2F3
It's r cubed, not tripled. meaning r*r*r
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288pi+=+4%2Api%2Ar%5E3%2F3
864+=+4r%5E3
r%5E3+=+216
r = 6 cm
Answer:
Afful is 21 and Naomi is 13.
Step-by-step explanation:
Let 
represent the age of Afful and 
represent the age of Naomi.
The sum of their ages is 34. In other words:
In 5 years time, Afful will be two times the age of Naomi <em>now</em>. In other words:
Solve for the system. Substitute.
Afful is currently 21 and Noami is currently 13.
