$54x^2-75x+-20$

$-5+2.\left[4.\left(3-5\right)+3\left(4-7\right)\right]$

$\lim_{x\to\infty}\left(1+\frac{7}{3x}\right)^{4x}$

$\lim_{x\to\infty}\frac{2x^4-7}{\sqrt{4x^8+7x^5}}$

$2x^2y+4yx^2-3x^2y+2x^2$

$\left(\frac{\left(6\sqrt{26}\right)}{26}\right)^{-1}$

$1+5x=-29$