Which table shows a constant of proportionality of 2 for the ratio of string instruments to percussion instruments?

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

Which expression is equivalent to -5(3x - 6/7)

Lola says these two expressions have the same value. expression a expression b which explains whether lola is correct?