[RoosterRedux]

I majored in math modeling and haven't found the error in Cboldts exercise.

It expands the problem when it should reduce it, but still, logic is logic.

Can you pinpoint the error in it?

[Cboldt]

The error is divide by zero.

If a + b = c, then a + b - c = 0

4(a + b - c) = 3(a + b - c) is true. It is 4*0 = 3*0, or 0=0

[Cletus.D.Yokel]

See my 422.

The error is equating the portion to the decimal.

Not having mathematical symbols, I’ll write it out:

One third (the portion) does NOT equal 1 divided by 3 (the decimal value).

[Swordmaker]

I majored in math modeling and haven't found the error in Cboldts exercise.

Te error is in the order in which the math was done. The mnemonic of "Please Excuse my dear Aunt Sally." or PEMDAS . . . Parentheses, Exponents, Multiplication, Division, Addition, Subtraction.

Had you done that, you would have found that the (a+b-c), reduces to equal zero. Because c was originally defined as being the sum of a+b=c. Therefore, subtracting c from a + b, negates the total of both.

Then, when you do the third step, there being no exponents to do, of multiplication, anything multiplied by ZERO, equals Zero, the correct result is 2(0) = 3(0) which then reduces to 0=0, not the claimed 2=3.

The example math, as shown, is erroneous due to failure to do the math by PEMDAS.