$f\left(50\right)=-2.1\left(50\right)+247$

$\left(x^6\cdot\frac{x^{10}}{x^{-3}}\right)^2$

$9a-a+5a-7a=6$

$2\left(x+1\right)-3\left(x+2\right)<x+6$

$\cos\left(2x\right)\cdot\cos\left(x\right)-\sin\left(x\right)\sin\left(2x\right)$

$8x^2+6x-4$

$\frac{5x-4}{18}-2\left(3x-5\right)\ge\frac{4x-7}{12}-\left(2x-1\right)$