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barbara's age is 5 years less than her brother's age if her age is increased by 3 times her brother's age the result is 51 years
find each of their age.
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The "josgarithmetic" solution is WRONG.
Let "x" be the Barbara's age, "y" be her brother age.
Then
x = y-5, (1)
x + 3y = 51. (2)
Substitute expression (1) into equation (2), replacing y. You will get
(y-5) + 3y = 51.
4y - 5 = 51 ---> 4y = 51 + 5 = 56 ---> y = = 14.
Thus the brother's age is 14 years. Then the Barbara's age is 14-5 = 9 years.
Answer. Barbara is 9 years. Her brother is 14 years.
There is a bunch of lessons on age word problems
- Age problems and their solutions
- A fresh formulation of a traditional age problem
- Really intricate age word problem
- Selected age word problems from the archive
in this site.
Read them and become an expert in solving age problems.
Also, you have this free of charge online textbook in ALGEBRA-I in this site
- ALGEBRA-I - YOUR ONLINE TEXTBOOK.
The referred lessons are the part of this online textbook under the topic "Age word problems".
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One notice at the end. The phrase
"Barbara's age is 5 years less than her brother's age."
doesn't sound harmonically/naturally in English. They say
"Barbara is 5 years younger than her brother."
Same for "find each of their age."