Help proportions if someone answers correctly ill give u brainliest!

What is x and y (use substitution? ) 5x+3y=38 and y=3x+8?

In which source of water would a wave travel the fastest? o ice o cold o room temperature o hot mark this and return save and exit next

Maria donates a fixed amount, a, to a charity each month. if she donates $300 in 12 months, what is the equation for a? a. a + 300 = 12 b. a × 300 = 12 c. a × 12 = 300 d. a + 12 = 300 e. a + 32 = 100