$$8xy;x=3;y=-2$$

$$-6\left(32\right)$$

$$\left(2x+5\right)^2-\left(x-1\right)^2$$

$$\frac{4x+87}{\left(x-8\right)\left(x+9\right)}$$

$$\int_0^1xe^{-x}dx$$

$$-8x+3\ge27$$

$$3\cos^2\left(x\right)+\sin^2\left(x\right)+5\sin\left(x\right)=0$$