 # Elementary Mathematical Equation

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• #2182832

And the lesson is – express yourself carefully – do not use Os for 0s and put parentheses in (2x)/(3y). Mathematicians know that. In Hardy/Littlewood book of math jokes, the professor (Hardy?) writes down an equation:

a x^4 + b x^3 + c x^2 + d x + e (similarly to ax + b, ax^2+bx+c, etc)

and then finds it necessary to add:
when e is any number, not necessarily the ln(1)
although it could take that value.

That’s _precision_ of speech.

#2182923
ujm
Participant

AAQ: How would you express the following equation more precisely (or is it simple enough, already)?

3-3×6+2

#2183034
Reb Eliezer
Participant

3 – (3 x 6) + 2 = 3 – 18 + 2 = -15 + 2 = -13

#2183045
ytvalumni
Participant

3-(3*6)+2 = 3-18+2 = 3-20 = -17

#2183067
Reb Eliezer
Participant

I have no idea what you talking about. By the commutative law 3 + 2 – 18 = 5 – 18 = -13
To get -17 it must be (3 – (18 + 2)) = 3 – 18 – 2 = 3 – 20 = -17

#2183230

> 3-3×6+2

+ 2 – 3 x 3 6

#2183240
Reb Eliezer
Participant

2 – 3×36 = 2 – 108 = -106

#2183330
Reb Eliezer
Participant

You can also write 3 – 20 = – (20 – 3) = -17

#2183331
Reb Eliezer
Participant

Also 2 – (3 X 36) = 2 – 108 = – (108 – 2) = – 106

#2184386
Meno
Participant

Problems like this are silly. They’re not math problems, they’re “follow the rules” problems. The rules are arbitrary. Tell me the rules and I’ll give you the answer.

#2184403
ujm
Participant

Meno, most math exam questions, whether in elementary school, high school or in university, are “follow the rules” problems.

#2184496
Reb Eliezer
Participant

The whole math is based on logical rules that are built on postulates. We cannot prove the existence of G-d without any accepted facts as described in Shaar Yichud of Chovas Halvavos.
Kant points out that it cannot be proven or dis-proven otherwise we would lose our bechira, free choice.

#2184601

> most math exam questions, whether in elementary school, high school or in university, are “follow the rules” problems.

this is what counts as math in many places, but that is not what math is.

My personal theory is that after Russkies sent Sputnik, US understood that we can lose the technology race to future missiles just with lawyers, so math was immediately introduced at all levels. Unfortunately, Khan Academy was not there yet, so who were the teachers in all these new classes? Same English teachers and unsuccessful lawyers. This generated a huge wave of people hating math teaching children hating math, and this became the mesorah. This is, l’havdil’ what happens when Jewish community grows, b’H so fast that not-very-educated teachers propagate through educational system, leading to higher minimal level, but not much at higher level.

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