Let x be the number of child tickets he bought
Let y be the number of adult tickers he bought
① x+y=7 (child tickets+adult ticket=7 tickets in total)
② 2x+4y=24 (price of child tickets+price of adult tickets=$24 in total)
We may simply the second equation since all of the coefficients are divisible by 2.
① x+y=7
② x+2y=12
We can now use elimination by multiplying the second equation by -1.
② -(x+2y=12)
② -x-2y=-12
① x+y=7
② -x-2y=-12
Now putting the equations together,
-y=-5
y=5
x=2
Therefore he bought 2 child tickets and 5 adult tickets
Answer:
+ 1) is an even number.
Take any n ∈ N, then n is either even or odd.
• Suppose n is even ⇒ n = 2m for some m ⇒ n(n + 1) = 2m(n + 1) ⇒ n(n + 1) is even.
• Suppose n is odd ⇒ n+ 1 is even ⇒ n+ 1 = 2m for some m ⇒ n(n+ 1) = 2nm ⇒ n(n+ 1)
is even. QED
2. The sum of the first n natural num
Step-by-step explanation:
a>50A is greater than 50
a<50a<50
a≥50A is greater than or equal to 50
a≤50
It was complicated but I did it
Answer:
smaller number = 3 5/24
larger number = 6 13/24
Step-by-step explanation:
let the larger number = x
smaller number = y
x - y = 3 1/3 equation 1
2(x +y) = 191/2 equation 2
divide equation 2 through by 2
x + y = 9 3/4 equation 3
subtract equation 1 from 3
2y = 6 5/12
y = 77/12 x 1/2 = 3 5/24
substitute for y in equation 1
x - 3 5/24 = 31/3
x = 3 1/3 + 3 5/24
x = 6 13/24
