Let's say each row has x desks and there are y rows.
We then know that x*y =25
We also know that x*2-5=y (number number of rows is five less than twice the number of desks in each row)
So we substitute: x*(x*2-5)=25
putting numbers out of the brackets:
2x*x-5x=25
2x*x-5x-25=0
(2x+5)(x-5)=0 (this bracketing is true: you can check it by expanding it:
2x*x-10x+5x-25
So that means that either x=-2.5which can't be : there can't be a fractional number of benches,
or x=5
so each row has 5 desks and there are 2*5-5 rows, or 5 rows.
Since 15409-1=15408 and 15408+1=15409, we can write that as one. With 15409-2, we can write the same thing with 15407+2
Answer:
12
Step-by-step explanation:
It is worthwhile memorizing the ratios of legs in a 30°–60°–90° triangle. Shortest to longest, the ratios are ...
1 : √3 : 2
Then the sides marked will have the ratio ...
6 : x = 1 : 2 = 6 : 12
x = 12
_____
You can also get there using trigonometry.
cos(60°) = 6/x
x = 60/cos(60° = 60/0.5
x = 12
Coke : sprite
4 : 5
(x5) (x5)
20 : 25
--------------------------------------------------------------------------------------------
Answer: There are 25 cans of sprite.
--------------------------------------------------------------------------------------------
