Geometry question!?

I dont know how to do this question.. HelpB is the midpoint of line ACAB=3x AC=7x-5 What is the value of BC?

since AC=7x-5.......and AC is the entire thing.....andsince AB=3x...........which is exactly half of the whole thingjust subtractand you get 4x-5

4x-5

well because of what it tells you, you knowAC - AB = BC7x - 5 - 3x = BC4x - 5 = BCand you know. AB = BC because a midpoint divides a line in 23x = 4x - 55 = xthen you plug it into BCBC = 4x - 5BC = 20 - 5BC = 15

on a line AC B is midpt.so,AB+BC=ACwhen-AB=3x &AC=7x-5BC=AC-ABi.e.7x-5-3x=0=>4x-5=0=>4x=5hence,bc=>4x-5 or 4x=5

AB + AB = AC 3x +3x= 7x - 56x = 7x - 55= x Substitute BC = 3(5) = 15