Please somebody else help me to do . I will mark the correct answer as a brainiest​

When you answer this can you explain

Two cyclists 84 miles apart start riding toward each other at the same. one cycles 2 times as fast as the other. if they meet 4 hours later, what is the speed (in mi/h) of the faster cyclist?

Rewrite the following quadratic functions in intercept or factored form. show your work. y = 4x^2 - 19x- 5