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:
15 weeks
The amount of money is 270
Step-by-step explanation:
You: 60 +14x
Sister: 120+10x
Set them equal to each other
60+14x = 120+10x
Subtract 10x from each side
60+4x= 120
Subtract 60 from each side
4x= 60
Divide by 4
4x/4 = 60/4
x = 15
15 weeks
The amount of money is 120+10*15 = 120+150 = 270
Answer:
The sum of reciprocals is 2/3.
You don't need complex numbers to solve this, but if you try to find a and b you will need complex numbers.
Step-by-step explanation:
a+b = 2
a*b = 3
1/a + 1/b = x
(a*b)*(1/a + 1/b) = (a*b)x
b + a = (a*b)(x)
2 = 3x
x = 2/3
b = 2 - a
a*(2 - a) = 3
-a^2 + 2a = 3
-a^2 + 2a - 3 = 0
a^2 - 2a + 3 = 0
let's solve the quadratic equation
a^2 - 2a + 3 = a^2 - 2a + 1 + 2 = (a - 1)^2 + 2 = 0
(a - 1)^2 = -2
these options correspond to a and b from the original question.
50
Step-by-step explanation:
Since AE is the bisector of angle BAC,so angle BAE and Angle CAE is equal. Here Angle CAE and Angle EAC is same.
therefore,
m(Angle BAE)=m(Angle EAC)
or, 2x=40
or, x=20
Hence,
m(Angle EAC)=
=
Answer: 48,60
Step-by-step explanation:
4x+5x=108
9x=108
x=108/9=12
12•4=48
12•5=60
