70/80 as a decimal is 0.875
Answer:
log₉2873 ≈ 3.6242
Step-by-step explanation:
First off all you can estimate by applying a fundamental property of a logarithm
Answer:
13
Step-by-step explanation:
Divide both sides by 7 so the multiplication cancels out.
Let the amount of shells collected by Aaron be

and the amount of shells collected by Maria be

respectively. Then the following system of equations should be solved:

First of all, express

out of first equation:

Then, replace

in second equation with found expression and solve it:



Finally, replace

in first equation with found value and solve it too:


So, Aaron has found
7 shells while Maria has found
21.
Answer:
0.448 seconds
Step-by-step explanation:
d = -16t² -4t + 412
find t when d = 407
substituting d = 407 into the equation:
407 = -16t² -4t + 412 (subtract 407 from both sides)
-16t² -4t + 412 - 407 = 0
-16t² -4t + 5 = 0 (multiply both sides by -1)
16t² + 4t - 5 = 0
solving using your method of choice (i.e completing the square or using the quadratic equation), you will end up with
t = (-1/8) (1 + √21)= -0.70 seconds (not possible because time cannot be negative)
or
t = (-1/8) (1 -√21) = 0.448 seconds (answer)