Find d^2 y/ d^2 x need help

Homework Statement

Find the d^2 y /d^2 x for y= 3t^3+4t and x=6t^4+7t

I just made one up similiar to what my teacher gave to do

The Attempt at a Solution

Dont know how to do it, i know i need 2nd derivatives but what then help i need please

Well first off find $$\frac{dy}{dt}$$ and $$\frac{dx}{dt}$$ and then try go at it from there. Use your knowledge of parametric differentiation.