Your proportion would be 13/3 =x/4,000.
Answer:
255
Step-by-step explanation:
They can buy petrol on all the days, so it must follow these following conditions.
Each of the digits less than 6.
Odd(the last digit can be 1,3, or 5).
Sum of the three digits greater than 10
Multiple of 3. This means that the sum of the digits must be divisible by 3.
Sum of the digits less than 15. So, between 11 and 14.
At least two of the digits are the same
Total value less than 500. Which means that the first digits can be from 1 to 4.
Following all these conditions
The answer is 255
Well, first lets get our terms straight.
There's no such thing as "cubic area".
-- The distance along a road is "length". That's how much string you need
to stretch from one end of the road to the other.
-- The amount of surface on a sheet of paper, a floor, or a front yard is "area".
That's how much paint or carpet you need to cover it.
-- And the space inside a balloon, a milk jug, or a room is the "volume".
That's how much water it takes to fill it up.
To find the volume of a room, measure its length, width and height,
and then multiply them all together.
Volume = (length) · (width) · (height) of the room.
If you measure the dimensions of the room in feet, then
the volume will be in cubic feet.
If you measure the dimensions of the room in inches, then
the volume will be in cubic inches.
If you measure the dimensions of the room in meters, then
the volume will be in cubic meters.
You could do the whole building the same way ... multiply its
(length) x (width) x (height) ... but there could be a big problem
trying to do that. You can only do it that way when the space is
the shape of a rectangular prism. That's the shape of an ice cube,
a Rubik's cube, a brick, a cigar box, a pizza box, a suitcase, a
shoe box ... things like that. If the building isn't the shape of a giant
brick or a shoebox, then it probably looks like a stack of several blocks
with different sizes. It might even have some curves on it, so you
can't just pick a length, a width, and a height and multiply them.
In that case, if you need to find the volume of the whole building,
you have two choices:
Choice #1). Get a drawing of the building, and see if it's possible to
break it up into smaller sections, with each section shaped like a brick
or a shoebox. For each section, multiply the (length x width x height)
of that section, and when you've done that for all the sections, add them
all up.
Choice #2). Measure the length, width and height of every room
in the building, use those to calculate the volume of each room,
and when you have them all, add them all up to get the volume of
the whole building.
How to solve your problem
x^{2}-21=100
Quadratic formula
Factor
1
Move terms to the left side
x^{2}-21=100
x^{2}-21-100=0
2
Subtract the numbers
x^{2}\textcolor{#C58AF9}{-21}\textcolor{#C58AF9}{-100}=0
x^{2}\textcolor{#C58AF9}{-121}=0
3
Use the quadratic formula
x=\frac{-\textcolor{#F28B82}{b}\pm \sqrt{\textcolor{#F28B82}{b}^{2}-4\textcolor{#C58AF9}{a}\textcolor{#8AB4F8}{c}}}{2\textcolor{#C58AF9}{a}}
Once in standard form, identify a, b, and c from the original equation and plug them into the quadratic formula.
x^{2}-121=0
a=\textcolor{#C58AF9}{1}
b=\textcolor{#F28B82}{0}
c=\textcolor{#8AB4F8}{-121}
x=\frac{-\textcolor{#F28B82}{0}\pm \sqrt{\textcolor{#F28B82}{0}^{2}-4\cdot \textcolor{#C58AF9}{1}(\textcolor{#8AB4F8}{-121})}}{2\cdot \textcolor{#C58AF9}{1}}
4
Simplify
Evaluate the exponent
Multiply the numbers
Add the numbers
Evaluate the square root
Add zero
Multiply the numbers
x=\frac{\pm 22}{2}
5
Separate the equations
To solve for the unknown variable, separate into two equations: one with a plus and the other with a minus.
x=\frac{22}{2}
x=\frac{-22}{2}
6
Solve
Rearrange and isolate the variable to find each solution
x=11
x=-11
