Question

Dau FUNDA!!! ab+bc = 69, a/8=b/12=c/15

Answer 1

a/8 =b/12 = c/15
a = 8b/12
c = 15b/12
ab + bc = 69
8b^2/12 + 15b^2/12 = 69 |×12
8b^2 + 15b^2 = 828
b^2(8+15) = 828
b^2 = 828 : 23
b^2 = 36
b = 6
a = 6×8/12 = 48/12 = 4
c = 6×15/12 = 90/12 = 7,5