Question

Salut va rog ajutati ma ex 14 si 15 puteti face doar una nu am deranjeaza.​

Answer 1

Răspuns:

Explicație pas cu pas:

14.

x = 9y/12 = 3y/4

z = 15y/12 = 5y/4

x^2 + y^2 = 9y^2/16 + y^2 = 9y^2/16 + 16y^2/16 = 25y^2/16 = (5y/4)^2 = z^2

______________

15.

11(2x + 3y) = 21(7x - 2y)

22x + 33y = 147x - 42y

33y + 42y = 147x - 22x

75y = 125x

x/y = 75/125 = 3/5

x = 3y/5

x + y = 3y/5 + y = 3y/5 + 5y/5 = 8y/5

x - y = 3y/5 - 5y/5 = -2y/5

(x + y)/(x - y) = 8y/5 : -2y/5 = -8y/5 * 5/2y = -4