$\frac{\left(5+6y\right)^4}{\left(1+15y\right)^2}$

$-2x^4+2=3x^2e^{3xy}$

$\log\left(x+4\right)-\log\left(x\right)=\log\left(3x\right)-\log\left(2\right)$

$\log_{100}\left(1+x\right)=\log\left(4x\right)-\log\left(\sqrt{8}\right)$

$-11x^2-4x^2$

$4\cdot49$

$10-\frac{x}{15}=16$