Answer:
i think its 10cm
Step-by-step explanation: brainlyest plz :)
90+80=170
180-170=10
<span>There are several ways to do this problem. One of them is to realize that there's only 14 possible calendars for any year (a year may start on any of 7 days, and a year may be either a leap year, or a non-leap year. So 7*2 = 14 possible calendars for any year). And since there's only 14 different possibilities, it's quite easy to perform an exhaustive search to prove that any year has between 1 and 3 Friday the 13ths.
Let's first deal with non-leap years. Initially, I'll determine what day of the week the 13th falls for each month for a year that starts on Sunday.
Jan - Friday
Feb - Monday
Mar - Monday
Apr - Thursday
May - Saturday
Jun - Tuesday
Jul - Thursday
Aug - Sunday
Sep - Wednesday
Oct - Friday
Nov - Monday
Dec - Wednesday
Now let's count how many times for each weekday, the 13th falls there.
Sunday - 1
Monday - 3
Tuesday - 1
Wednesday - 2
Thursday - 2
Friday - 2
Saturday - 1
The key thing to notice is that there is that the number of times the 13th falls upon a weekday is always in the range of 1 to 3 days. And if the non-leap year were to start on any other day of the week, the numbers would simply rotate to the next days. The above list is generated for a year where January 1st falls on a Sunday. If instead it were to fall on a Monday, then the value above for Sunday would be the value for Monday. The value above for Monday would be the value for Tuesday, etc.
So we've handled all possible non-leap years. Let's do that again for a leap year starting on a Sunday. We get:
Jan - Friday
Feb - Monday
Mar - Tuesday
Apr - Friday
May - Sunday
Jun - Wednesday
Jul - Friday
Aug - Monday
Sep - Thursday
Oct - Saturday
Nov - Tuesday
Dec - Thursday
And the weekday totals are:
Sunday - 1
Monday - 2
Tuesday - 2
Wednesday - 1
Thursday - 2
Friday - 3
Saturday - 1
And once again, for every weekday, the total is between 1 and 3. And the same argument applies for every leap year.
And since we've covered both leap and non-leap years. Then we've demonstrated that for every possible year, Friday the 13th will happen at least once, and no more than 3 times.</span>
9514 1404 393
Answer:
47 -6√10
Step-by-step explanation:
As you know, the area of a square is the square of the side length. It can be helpful here to make use of the form for the square of a binomial.
(a -b)² = a² - 2ab + b²
(√2 -3√5)² = (√2)² - 2(√2)(3√5) + (3√5)²
= 2 - 6√10 + 3²(5)
= 47 -6√10
__
<em>Check</em>
√2-3√5 ≈ -5.29399 . . . . . . . . note that a negative value for side length makes no sense, so this isn't about geometry, it's about binomials and radicals
(√2-3√5)² ≈ 28.02633
47 -6√10 ≈ 28.02633
Answer: 1.4 seconds
<u>Step-by-step explanation:</u>
The equation is: h(t) = at² + v₀t + h₀ where
- a is the acceleration (in this case it is gravity)
- v₀ is the initial velocity
- h₀ is the initial height
Given:
- a = -9.81 (if it wasn't given in your textbook, you can look it up)
- v₀ = 12
- h₀ = 3
Since we are trying to find out when it lands on the ground, h(t) = 0
EQUATION: 0 = 9.81t² + 12t + 3
Use the quadratic equation to find the x-intercepts
a=-9.81, b=12, c=3
Note: Negative time (-0.2) is not valid
