$\sin30+\csc^230-2\cot45$

$12k\:+\:60k\:2\:+\:75k$

$8x^3+3\left(4x\right)^2+3\left(2x\right)\left(1\right)^2+1^3$

$\left(1-\sin^2x+\cos^2x\right)^2+4\sin^2x\cos^2x=4\cos^2x$

$\int\:\left(\frac{3}{x^2}+\frac{x^3}{5}+2\right)dx$

$49x^2-4y^2$

$\:\left(-12\right)\left\{45+6\left(-12\right)-\left(-3\left(6\right)+9\right)\left[24-\left(-5\right)\left(-4\right)\right]\right\}$