Question

If 3a+c=5b and 3a +5b+c=80, what is the value of b?

Answer 1

8
10
15
20
needs more info.

Answer 2

3a+c=5b

3a+5b+c=80
3a+c+5b=80

3a+c can be written as 5b

5b+5b=80
10b=80
divide both sides by 10

so b= ?

Answer 3

Shouldn't it be -5b?

Answer 4

Why ?

Answer 5

Because it needs to equal to 80, and the 5b needs to get to the other side

Answer 6

No
3a + c =5b <-- this is first equation (1)

Now
3a+5b+c=80
it can be written as
3a+c+5b=80 (just rearranging )
(3a+c)+5b=80

Now what is 3a+c ?? 3a +c =5b ( from equation (1) )
So substitute it here

(5b)+5b=80
10b=80
divide both sides by 10 and b= ?

Answer 7

8

Answer 8

Right :D

Answer 9

Thanks! :) @Diyadiya

Answer 10

Anytime =)