$$7x^2-7y=3$$

$$2f+f$$

$$\left(x^2+1\right)\left(x^4+x^2+1\right)$$

$$\cos\left(x\right)-2\sin\left(x\right)\cos\left(x\right)+\cos\left(x\right)\sin\left(x\right)^4$$

$$3a+b-2b$$

$$x^2-14x\le-49$$

$$a^10-2a^5+1$$