Cara likes candles. She also likes mathematics and was thinking about using algebra to answer a question she had about two of her candles. Her taller candle is 16 cm tall. Each hour it burns makes the candle lose 2.5 cm in height. Her short candle is 12 cm tall and loses 1.5 cm in height for each hour that it burns. Write an equation for both candles and solve it by either substitution or elimination.

(If someone could please help me out with this, I would really appreciate it. I've been trying to do this for days now and I just can't figure it out..)
(By the way, the equation for the 16 cm candle is y = -2.5x + 16, and the equation for the 12 cm candle is y = -1.5x + 12, I just don't know how to solve it using substitution or elimination.)​