Se compran 30 libros a S/ 720, si se pierden 10 libros, ¿a cuánto debo vender cada uno de los restantes para ganar un total de S/180?

step-by-step explanation:

let pq = qr = rs = x, and xz = y and zu = z.

if the horizontal lines are parallel, then corresponding segments are in proportion:

substitute:

therefore 3 = y = z.

xu = y + z → xu = 3 + 3 = 6

3.07*10^-4

move the decimal 4 places to the left

.000307

check