The answer to this questions is letter B
Answer: 46 years
Step-by-step explanation:
Let the father's age be x and the son's age be y, then 3 years ago:
Father = x - 3
son = y - 3
Then , from the first statement :
x - 3 = 3 ( y - 3 )
x - 3 = 3y - 9
x = 3y - 9 + 3
x = 3y - 6 .......................................... equation 1
In five years time
father = x + 5
son = y + 5
Then , from the second statement
x + 5 = 2 ( y + 5 )
x + 5 = 2y + 10
x = 2y + 10 - 5
x = 2y + 5 ........................ equation 2
Equating equation 1 and 2 , we have
3y -6 = 2y + 5
add 6 to both sides
3y = 2y + 5 + 6
subtract 2y from both sides
3y - 2y = 11
y = 11
substitute y = 11 into equation 1 to find the value of x
x = 3y - 6
x = 3(11) - 6
x = 33 - 6
x = 27
This means that the father is presently 27 years and the son is presently 11 years.
In four years time
father = 27 + 4 = 31
son = 11 + 4 = 15
sum of their ages in four years time will be
31 + 15 = 46 years
Answer:
I think it is the last one 4-6
What is the commutative property of multiplication?
The college student took 13 courses of 3 credit hours.
Step-by-step explanation:
Given,
Total credits = 59
Total courses = 18
Let,
Number of 3 credit hour courses = x
Number of 4 credit hour courses = y
According to given statement;
x+y=18 Eqn 1
3x+4y=59 Eqn 2
We will eliminate y to find the number of 3 credit hour courses, therefore,
Multiplying Eqn 1 by 4

Subtracting Eqn 2 from Eqn 3

The college student took 13 courses of 3 credit hours.
Keywords: linear equation, subtraction
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