Question 1120415: For what value of the variable will the value of x be three times less than the value of 45−10x?
Found 2 solutions by Boreal, greenestamps:
Answer by Boreal(15235)   (Show Source):
You can put this solution on YOUR website! If 3 x less means 1/3 as much
then x*3<45-10x
13x<45
x<45/13, which is about 3.46
so 3.46 vs 45-34.6 is 3.46<(1/3)10.4, with the exact value 45/13< 45-(450/13), which is 3*45/13<135/13. That is the equality, so any x less than 45/13 will be correct.
Answer by greenestamps(13200)  (Show Source):
You can put this solution on YOUR website!
(Note: the other tutor misread the problem; there is no inequality in this problem....)
In reality, the problem can't be answered, because the phrase "three times less than" does not mean what the problem intends it to mean.
Presumably, if the phrase is used in its nonsensical everyday way, three times less than means 1/3 as much:
I have $15; you have 3 times less than I have. So the amount you have is 1/3 of $15, or $5.
But grammatically three times less than means something completely different:
I have $15; you have 3 times less than I have. So the amount you have is what I have ($15), minus three times that amount ($45), which means the amount you have is -$30.
That is nonsense...!
Any math problem that uses the phrase "x times less than" is an invalid problem, because the intended meaning is almost certainly not the real meaning.
This problem can be worked using the real meaning of the given information; but the result is almost certainly not the intended answer.
The given information, correctly interpreted, means that x is three times less than (45-10x).
Three times less than (45-10x) is
(45-10x) - 3(45-10x) = 20x-90
Then the equation says
x = 20x-90
19x = 90
x = 90/19
|
|
|
