Intereting Posts

Can I soundly define a function which maps to itself?
Constructing a sequence of function
The group $\mathbb Q^*$ as a direct product/sum
Matrix non-identity
How can I show that $y'=\sqrt{|y|}$ has infinitely many solutions?
What is the importance of the Collatz conjecture?
$I_m – AB$ is invertible if and only if $I_n – BA$ is invertible.
What is the topological dual of a dual space with the weak* topology?
Find conjugation invariant functions without using eigenvalues?
How to prove that $p-1$ is squarefree infinitely often?
Proof that Every Positive Operator on V has a Unique Positive Square Root
What is $\mathbb{C}^{Aut(\mathbb{C}/\mathbb{Q})}$?
$ \int_1^2\int_1^2 \int_1^2 \int_1^2 \frac{x_1+x_2+x_3-x_4}{x_1+x_2+x_3+x_4}dx_1dx_2dx_3dx_4 $
are there non-standard models of arithmetic in second order arithmetic?
Can we construct a function $f:\mathbb{R} \rightarrow \mathbb{R}$ such that it has intermediate value property and discontinuous everywhere?

Very dumb question:

What is the order of operations in the following:

PEMDAS a/b+c = a : b + c (where “:” is the division symbol)

- Is it possible to practice mental math too often?
- If $x$ is a positive integer such that $x(x+1)(x+2)(x+3)+1=379^2$, find $x$
- The last digit of $n^5-n$
- which is larger number? $\sqrt{7}-\sqrt{6}$ or $\sqrt{6}-\sqrt{5}$
- How much faster is the Trachtenberg system?
- Convergents of square root of 2

7/1+6 or 7:1+6

in the example below is it 1 or 13?

- What are some examples of notation that really improved mathematics?
- What does **Ens** stand for?
- The logarithm is non-linear! Or isn't it?
- Show that $\sqrt{3\sqrt{21} + 8} - \sqrt{3\sqrt{21} - 8} = 1$
- About the addition formula $f(x+y) = f(x)g(y)+f(y)g(x)$
- Dividing by 2 numbers at once, what is the answer?
- Find the coefficient of $w^{3}x^{5}z^{2}$ in the expansion of $(w+x+y+z)^{10}$
- What does E mean in 9.0122222900391E-5?
- What is the standard interpretation of order of operations for the basic arithmetic operations?
- When should I use $=$ and $\equiv$?

It is better written as $\dfrac{a}{b}+c$ or $(a/b)+c$ to avoid such possible ambiguity, assuming that is what it means (else, $a/(b+c)$ or $\dfrac{a}{b+c}$). I think we can all agree that, for example, $ab+c$ is shorthand for $(ab)+c$ rather than $a(b+c)$, but division with `/`

(or `÷`

) can add human parsing problems if parentheses are not used. See also Gerry Myerson’s answer to a related question.

First use PEMDAS and if two operations of same precedence occurs then Standard order convention is to evaluate from left to right.Here, division precedes over addition and hence answer is 13.

- Differentiable manifolds as locally ringed spaces
- How to calculate the following limit: $\lim_{x\to+\infty} \sqrt{n}(\sqrt{x}-1)$?
- Why is recursion theory suffering from terminological bloat?
- Why is $|Y^{\emptyset}|=1$ but $|\emptyset^Y|=0$ where $Y\neq \emptyset$
- Prove there is no contraction mapping from compact metric space onto itself
- Normal operator + only real eigenvalues implies self-adjoint operator?
- In which case $M_1 \times N \cong M_2 \times N \Rightarrow M_1 \cong M_2$ is true?
- The sequence $a_n = \left(\frac{n}{n+1}\right)^{n+1}$ is increasing
- How can I prove the convergence of a power-tower?
- Closed sum of sets
- Proving by induction that $ \sum_{k=0}^n{n \choose k} = 2^n$
- How to find $\int_{0}^{1}\dfrac{\ln^2{x}\ln^2{(1-x)}}{2-x}dx$
- Importance of Constructible functions
- Circular logic in set definition – Tautology?
- $ax+by+cz=d$ is the equation of a plane in space. Show that $d'$ is the distance from the plane to the origin.