Question

Aflați Nr nat x din proporțiile b) x+5/11 =x/6 c) x/8=x+9/11 d)x/9=x,+8/13

Answer 1

Dacă ai un raport in care îți zice a/b=c/d il afli facand a×d=b×c

Answer 2

b) (x+5)/11 = x/6

6(x+5) = 11x

6x+30 = 11x

6x-11x = -30

-5x = -30

x = 6

c) x/8 = (x+9)/11

11x = 8(x+9)

11x = 8x+72

11x -8x = 72

3x = 72

x = 72/3

x = 24

d) x/9 = (x+8)/13

13x = 9(x+8)

13x = 9x+72

13x-9x = 72

4x = 72

x = 72/4

x = 18