Answer:
20 adults and 10 children
Step-by-step explanation:
We need to find the total amount of adults and children for 30 total people (adults + children) and only 100$ for them. 30 adults is 120$. We need to take off double the amount of money that would bring it to 100$ because the cost for each child is half of an adult. That way, we have 80$ of adults, and when we fill in the rest with children, we get to 100$ total and 30 total people.
Answer:
The first number is 20, the second one is 11
Step-by-step explanation:
Let the first number be x and the second number be y
Since it says "9 is the difference between two numbers", the first equation will be x-y=9
It also says that "their sum is 31". That means the second equation will be x+y=31
here are the two equations:
x-y=9
x+y=31
You can solve this any way you like, but I'll show elimination
add the two equations
x-y=9
x+y=31
2x=40
divide by 2
x=20
Substitute 20 as x in one of the equations
20+y=31
subtract 20 from both sides
y=11
That means the two numbers are 20 and 11
Hope this helps!
Answer:
312
Step-by-step explanation:
Volume of the parallalelepiped:
base x width x height
V = 5 x 4 x 12 = 240
for triangular prism:
base = 8-5 = 3
base area = (base x height)/2 = (3x4)/2 = 6
V = base area x 12
V = 6 x 12 = 72
Total volume = 240 + 72 = 312
Answer:
The longer piece: 54m
The shorter piece: 19m
Step-by-step explanation:
Make an equation from what is said.
One of the pieces is 'x'
The other piece is 2x+16
x + (2x + 16) = 73m
solve for x
x = 19
plug it in
2*19 + 16
you get 54
so 54 is the longer piece
and 19 is the shorter piece (x was the shorter piece)
Hope this helped :)
We collect like terms
8x - 3x = 3 + 5 + 9
This is bcos if a (-) sign crosses the equals sign it becomes a (+), and if a (+) sign crosses the equals sign it becomes (-)
We the have
5x = 17
Divide both sides by 5
x = 17/5
x = 3.4
