Answer:
their marriage and 2 years before
To be a function each different x value would have a different Y value.
First one is a function, there are no repeated Y values.
The second one is a function.
Third one is not a function because it has two identical Y values with different x values.
The fourth one is a function.
The data is not linear. From (3, 1) to (7, 2), we add 4 to the x-value and add 1 to the y-value. This pattern continues for a little while, however, from (11, 3) to (18, 5), we add only 7 to the x-value even though we added 2 to the y-value. Given this information, we can determine that this is not linear data.
The present age of mother and her daughter respectively are; 40 and 10 years respectively.
<h3>How to Solve Algebra Word Problems?</h3>
Let x and y be the present age of mother and her daughter respectively.
Therefore;
x + y = 50
x = 50 − y .....(1)
After 20 years, mother's age will be twice her daughter's age at the time. Thus;
x + 20 = 2(y + 20)
x − 2y = 20 .....(2)
Plugging eq 1 into eq 2 gives us;
50 − y − 2y = 20
3y = 30
y = 10
Thus;
x = 50 − 10
x = 40
Thus, the present age of mother and her daughter is 40 and 10 years respectively.
Translation of the question into English is;
The sum of the present ages of mother and her daughter is 50 years. After 20 years, mother's age will be twice her daughter's age at the time. Find their present ages.
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