A ratio of 5:7 means out of 12 books, 5 are in one category and 7 are in another. (The “category” isn’t specified in this problem.)
So here we’re STARTING with 36 books; we want to find a ratio that is equal to 5:7 and adds up to 36. Well 36 = 3(12), and so if we multiply each number in the ratio by 3 as well, we might get what we want. Doing that gives us 15:21, which adds up to 36 and is equal to 5:7. Boom, that’s the answer.
P.S. Here’s a question you can think about: why do ratios stay the same when you multiply each number by the same amount? (For example, why is 3:1 the same as 6:2?)
Answer:
The length of the rectangle is 18 cm
The width of the rectangle is 6 cm
Step-by-step explanation:
Let
x-----> the length of the rectangle
y----> the width of the rectangle
we know that
The perimeter of the rectangle is

we have

so
------> equation A
------> equation B
Substitute equation B in equation A and solve for y
48=2(2y+6+y)
48=2(3y+6)
48=6y+12
6y=48-12
y=36/6=6 cm
Find the value of x
x=2(6)+6=18 cm
The area of the rectangle is
A=xy
A=18*6
A=108 cm^2
Answer:
subtract them
Step-by-step explanation: