Could i get work and explanation?

Write an equation in slope intercept form of the line passes through the given point and is parallel to the graph of the given equation (0,0); y=3/8 x+2

Kayla and alberto are selling fruit for a school fundraiser. customers can buy small boxes of grapefruit and large boxes of grapefruit. kayla sold 3 small boxes of grapefruit and 1 large box of grapefruit for a total of $65. alberto sold 1 small box of grapefruit and 1 large box of grapefruit for a total of $55. what is the cost each of one small box of grapefruit and one large box of grapefruit?

Given the two similar triangles, how do i find the missing length? if a=4, b=5, and b'=7.5 find a'