Find all pairs of $a$ and $b$ such that $ab = a+b$
35066
Nature and number of solutions to $xy=x+y$
12927
$A^2+B^2=AB$ and $BA-AB$ is non-singular
19656
Proving that $ \gcd(a,b) = as + bt $, i.e., $ \gcd $ is a linear combination.
110408
Solving for $A$ in $Ax = b$
24856
Proving sup(A + B) = sup A + sup B
130381
bijection from $(a,b)$ to $\Bbb R$
45979
Deﬁne a new addition ⊕ and multiplication on Z by a⊕b = a + b−1 and ab = a + b−ab.
72256
Prove there exists two sub-sets of indices $I,J\subseteq [2n]$ such that $\sum_{i\in I}a_i=\sum_{j\in J}b_j$
60006
Matrix equation: $A−A(A + B)^{−1}A = B−B(A + B)^{−1}B$
126018
Show that $ e^{A+B}=e^A e^B$
149939
Number of ordered pairs $(a,b)$ such that $ab \le 3600$
84422
$AB=BA$, $AC=CA$ we need to show $BC=CB$
133699
Proving that there is a bijection between $A$ and $B$.
128990
Prove that, at least one of the matrices $A+B$ and $A-B$ has to be singular
104068
Prove that $\forall a,b\in\mathbb{C} \exists c,d \in \mathbb{C}: c+d = a \land cd = b$
60707
Show that if $ \ A \cup B = A$ and $ \ A\cap B = A$ then $ \ A = B$
57125
Prove the distributive law $a(b+c)=ab+ac$ for real numbers?