First we need to factor the left side. Since it is a perfect square (as is the process with completing the square, we know we can take half of the middle number along with x to be in the two parenthesis.
(x - 4)(x - 4) = 25
Now we simplify to show it as a square.
(x - 4)^2 = 25
Next we take the square root of both sides
x - 4 = +/- 5
Note that we have plus or minus 5. This is because either square would give us positive 25. Now we add 4 to both sides
x = 4 +/- 5
4 + 5 = 9
4 - 5 = -1
Answer:
mary=10 jack=15
Step-by-step explanation:
After 4 years Mary (x+4), Jack's age (x+5) + 4.
sum of the ages after 4 years :(x+4) + (x+5) +4=33
Simplifying the equation:
2x+13 = 33 ----->> 2x=20----->>>>x = 10 Mary's age
10 + 5 = 15 which is Jack's age.
If the half-life is t, then every t days, the amount of the radioactive isotope will be cut in half.
(1/2)^(number of half-lives) = 3%
number of half-lives = ln(0.03) / ln(0.5)
This gives the number of half-lives as 5.06.
Then 300 days = (5.06)(length of 1 half-life)
length of 1 half-life = 300 / 5.06 = 59.29 days
Answer:
C=0.55M+24.65
Step-by-step explanation:
0.40M+0.15M=0.55M
18.95+5.70=24.65
Formula for the perimeter of a quarter circle: C = ((pi x 2r) / 4) + 2r
C = ((3.14 + 12) / 4) + 12
C = 3.785 + 12
C = 15.79 meters
Hope this helps! :)
