Day 1 - 100
Day 2 - 50
Day 3 - 25
Day 4 - 15
Day 5 - 10
Day 6 - 5
Day 7 - 2.5
Unit digit=y
tens digit=x
the number: 10x+y
We suggest this system of equations:
x+y=7
(10y+x)=(10x+y)+9
we solve it by substitution method.
x=7-y
10y+(7-y)=(10(7-y)+y)+9
9y+7=70-10y+y+9
9y+10y-y=70+9-7
18y=72
y=72/18=4
x=7-y
x=7-4=3
number=10x+y=10*3+4=30+4=34
solution: the number: 34
To check:
3+4=7
43=34+9
Answer:
341 ÷ 0.28=1217,85714286
Step-by-step explanation:
<h3>E
xplanation:</h3>
Replace cos^2(θ) with 1-sin^2(θ), and cot(θ) with cos(θ)/sin(θ).
cos^2(θ)cot^2(θ) = cot^2(θ) - cos^2(θ)
(1 -sin^2(θ))cot^2(θ) = . . . . . replace cos^2 with 1-sin^2
cot^2(θ) -sin^2(θ)·cos^2(θ)/sin^2(θ) = . . . . . replace cot with cos/sin
cot^2(θ) -cos^2(θ) = cot^2(θ) -cos^2(θ) . . . as desired
There are 26 letters of the alphabet
you want 6-character passwords without repetitionthe first time you pick a letter, you pick from 26 lettersthe second time you pick a letter, you pick from 25 letters (no repetitions !)the third time you pick a letter, you pick from 24 letters, and so onthe answer is 26*25*24*23*22*21=165,765,600 passwords
