Answer:
470 balls
Step-by-step explanation:
Let the number of tennis balls Kerns have be x and the number of tennis balls Hardy has be 3x. We want to find their difference: 3x-x = 2x
Total no. of balls = Kerns + Hardy
= x + 3x
= 4x
4x = 940
2x = × 940
= 470
the weight of the substance after 28 years is 8 grams.
<h3>How to determine the amount</h3>We have that the half life of a substance is defined as the time required for the substance to decrease by half
The formula for calculating the half - life of a material is given as;
Where
Substitute into the formula
N(t) = 128 × (0. 5) ^28/ 7
N (t) = 128 × ( 0. 5) ^ 4
N(t) = 128 × 0. 0625
N(t) = 8 grams
Thus, the weight of the substance after 28 years is 8 grams.
Learn more about half life here:
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What is the equation of the line that passes through (-3, 6) and has a slope of -2?
First, we need to write the equation of the line in point-slope form:-
Replace y1 with 6, m with -2, and x1 with -3:-
On simplification,
On further simplification,
Add 6 on both sides:-
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