Posted by katya on Saturday, September 19, 2009 at 4:59pm.
Let the first number be x
"The second number is 4 more than two times the first number"
the second number is 2x + 4
"The third number is five less than three times the first number"
the third number is 3x - 5
your first sentence "The Sum of three numbers is 147"
x + 2x+4 + 3x-5 = 147
6x = 148
x = 74/3
then second number is 2(74/3) + 4 = 160/3
the third number is 3(74/3) - 5 = 39
check: 74/3 + 160/3 + 69 = 147
Call the numbers A, B and C
We know
A + B + C = 147
We are told that:
B = 2 A + 4 (two times the first number and add 4)
and
C = 3 A - 5 (five less than three times the first number)
This is called substituting. Now we can substitute (2 A + 4) for B whenever we see it.
Using this, we can rewrite
A + B + C = 147
as
A + (2 A + 4) + (3 A - 5) = 147
since we know B and C in terms of A.
Make sure you understand this step before continuing.
Gathering the As and the numbers together, we have:
A + 2A + 3A + 4 - 5 = 147
6 A + 4 - 5 = 147.
6 A - 1 = 147.
6 A = 148.
A = 148 / 6.
A = 24 2/3
B = 2 A + 4 = 49 + 4 + 1/3 = 53 1/3
C = 74 - 5 = 69.
Related Questions
algebra - Five times the smallest of three consecutive odd integers is ten more ...
Grade 8 Math - Can you write them in Mathematical/numbers form I'll solve ...
advance algebra - find three numbers such that the second is 6 less than 3 times...
Math - The sum of three numbers is 301. The second number is 3 less than twelve ...
10th grade math - The sum of three numbers is 301. The second number is 3 less ...
math - the sum of 3 numbers is 301. the second number is 3 less than 12 times ...
math - Hi, for the question, "the sum of two numbers is equal to a third ...
math - The greater of two numbers is 1 more than twice the smaller. Three times ...
Math 0098 - The sum of three numbers is 113 . The second number is 3 times the ...
basic math problem - the sum of three numbers is 8. the first number plus the ...
For Further Reading
