-3b+ac=4
Move c to the left and - 3b to the right
ac-c=-4+3b
Now factor by c at the left
c(a-1)=-4+3b
Divide the right by a-1
C=(-4+3b)/(a-1)
Answer:
90
Step-by-step explanation:
To find s4 we find sum of values when n=1,n=2,n=3,n=4
given expression is 
n=1 , plug in 1 for n

n=2

n=3

n=4

Sum of all 4 terms = 6+12+24+48=90
Step-by-step explanation:
explain step by step on photo, double check just in case
5+(x-5)=x
Simplify the left side by combining like terms:
5 + x - 5 = x
5-5 = 0
x = x
X = All real numbers.