Question

(a+b):(b+c):(c+a)=7:8:9,a+b+c=18,a:b:c=??
answer with steps

Answer 1

(a+b):(b+c)=7:8
(a+b)/(b+c)=7/8
cross multiplication
8a+8b=7b+7c
8a+b-7c=0_equation 1

a+b+c=18
a=18-b-c

equation 1
8(18-b-c)+b-7c=0
144-8b-8c+b-7c=0
144-7b-15c=0
7b+15c=144_equation 2

(b+c):(c+a)=8:9
(b+c)/(c+a)=8/9
9b+9c=8c+8a
9b+c-8a=0
8a-9b-c=0

8(18-b-c)-9b-c=0
144-8b-8c-9b-c=0
144-17b-9c=0
17b+9c=144_equation 3
9c=144-17b
c=144-17b/9

equation 2
7b+15((144-17b)/9)=144
[63b+15(144-17b)]/9=144
63b+2160-255b=1296
-192b=-864
b=9/2

c=[144-17(9/2)]/9
c=[288-153]/18
c=135/18
c=15/2

a=18-b-c
a=18-9/2-15/2
a=[36-9-15]/2
a=12/2=6


a:b:c=6:9/2:15/2
=12:9:15

Answer 2

Answer:

answer is 4:3:5 this is answer