$-4-\left(2+4\right)$

$\left(x\right)=2x^5-x^3+x+7x^2+3x^4$

$3x^4y^3+z^2-7y^3x^4+2z^2$

$\left(4x^2-6y^2-9\cdot\left(-\frac{1}{3}\cdot x+\frac{13}{9}\cdot y+13\right)^2\right)\cdot13$

$\left(16x+2\right)\left(16x-2\right)$

$\left(4x+5y^2w+7z\right)-\left(8x+3z+2y^2w\right)$

$15-23-\left(-11\right)-34+19-\left(-35\right)-27$