Suppose that Eldi has x years old now :
x + 4 = 3 × ( x - 10 )
x + 4 = 3x - 30
Add both sides 30
x + 4 + 30 = 3x - 30 + 30
x + 34 = 3x
Subtract both sides x
x - x + 34 = 3x - x
34 = 2x
2x = 34
Divide both sides by 2
2x ÷ 2 =34 ÷ 2
x = 17
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Thus Eldi is 17 .
First add 5 to 16, so -3x=21
then divide by -3, so the answer is
x= -7
Answer:
C. two thirds x + 10 = 21
Step-by-step explanation:
Given
Price of adult ticket = $21.00
Let x be the price of student ticket
Then
two third of the student ticket will be:

The statement $10.00 more than two third of student ticket:

As we are given in the question that the adult ticket price is $21.00 and the second explanation is th equation formed by the given statement
So, both will be equivalent

Solving this equation for x will give us the price for the student ticket.
Hence,
C. two thirdsx + 10 = 21 is the correct answer ..
The results of an analysis, on the makeup of garbage, done by the Environmental Protection Agency was published in 1990. Some of the results are given in the following table, which for various years gives the number of pounds per person per day of various types of waste materials.