The sum of three numbers is 123 The second number is 4 times the first. The third number is 12 less than the second. What is the second number?

the second number is 60

Step-by-step explanation:

f = first s = second t=third

f+s+t=123

s=4f

t=s-12

lets get everything in terms of s

f=s/4

t=s-12

now plug those back into the original equation

(s/4) + s + (s-12) = 123

add 12 to both sides and you get

(s/4) + 2s=135

multiply everything by 4

s+8s=540

9s=540

s=60