$\frac{csc\left(x\right)^2-sen\left(x\right)^2}{csc\left(x\right)^2.\left(2-cos\left(x\right)^2\right)}$

$\left(4x^2-x+6\right)-\left(-3x^2+5x+2\right)$

$\frac { a ^ { 3 } + 2 ^ { 3 } } { a + 2 }$

$5+4\cdot4$

$\left(f-5\right)\left(f+4\right)$

$1.8\cdot0.8$