Answer:
Lixin obtains 15 marks
Step-by-step explanation:
Lets write two equations based on the question where: <u>D= Devi and L=Lixin</u>
D=L+15 <em>- "devi scores 15 marks more than lixin"</em>
D=2L <em>- "devi obtains twice as many marks as lexin"</em>
Now, substitute 2L as D in the first equation we wrote: (D=L+15)
2L=L+15
Next, subtract L from both sides:
<u>L=15</u>
Answer:
x = 30
Step-by-step explanation:
-2x + 10 +4x=70
-10 -10
-2x + 4x = 60
2x = 60
/2 /2
x = 30
<u>Answer:</u>
Michelle purchased 25 audio files in January. The percent increase is 60%
<u>Solution:
</u>
Given Data:
Michelle purchases = 25 audio files in January
Again purchased = 40 audio files in February
We need to find the percent increase for the given data.
Step 1:
Use the formula for percent change
,
Step 2:
First we find the amount of change from the question.
Amount of change = 40 – 25
By subtracting, we get 15.
Step 3:
substitute the values in formula we get,
Formula percent change = 
= 0.6
Percent = 0.6 
100 = 60 %.
Result:
Michelle purchased 25 audio files in January. And In February she purchased 40 audio files. Hence the percent increase is 60%.
Answer:
large tank volume = 6 litres
small tank volume = 3 litres
Step-by-step explanation:
Given that,
The combined volume of 3 large tanks and 2 small tanks is 24 litres.
The combined volume of 2 large tanks and 3 small tanks is 21 litres.
Suppose large tank volume = x
Suppose small tank volume = y
<h2>First Equation </h2>
3x + 2y = 24
<h2>Second Equation </h2>
2x + 3y = 21
Now solve them
3x =24 - 2y
x = (24 -2y) / 3
Put value of x in second equation
2 {(24 -2y) / 3} + 3y = 21
2(8) - 4y/3 +3y = 21
16 - 4y/3 + 3y = 21
3y -4y/3 = 21-16
5y/3 = 5
5y = 15
y = 15/5
y = 3
3x = 24 - 2(3)
3x = 18
x = 6
Answer:
Step-by-step explanation:
8.3
9.1
10.4
