Question

ab+bc= 69, a/8 = b/12 = c/15. Sa se afle numerele

Answer 1

ab +bc = 69
b(a+c) = 69

a/8 = b/12 = c/15
a = 8b/12 = 2b/3
c = 15b/12 = 5b/4

b(2b/3 + 5b/4) = 69
b( 8b/12+15b/12) = 69
b × 23b/12 = 69
23b^2 = 69×12
23b^2 = 828
b^2 = 828 : 23
b^2 = 36
b = 6
a = 2×6/3 = 4
c = 5×6/4 = 30/4 = 7,5

a = 4
b = 6
c = 7,5