1. Fredrick Kendrick Electric Circuits Fundamentals ET1410
Series-Parallel Circuits ® ©
R2+3 = R2 + R3 = 47Ω + 47Ω = 94Ω
R4||5 + R4R5 / R4 + R5 = 68Ω * 39Ω / 68Ω + 39Ω = 2.6523 / 107 = 24.8Ω
R4||5+6 = R6 + R4||5 = 75Ω + 24.8Ω = 99.8Ω
Simplified Equivalent Below:

2. Fredrick Kendrick Electric Circuits Fundamentals ET1410
First check it:
1 / 94 = 10.6-3 (1/X) = 94
1 / 99.8 = 10.02-3 (1/X) = 99.8
10.6-3 + 10.02-3 = 20.62-3
1 / 20.62-3 = 48.4
Last step:
100Ω + 48.4Ω = 148.4Ω
Find Current:
It = Vs / Rt
10V / 148Ω = 67.6mA
Instructed By: Don Heller. ET1410 Electrical / Electronic Engineering. (Book)
Electric Circuits Fundamentals. By: Thomas L. Floyd & David M. Buchla. Pg. 226.
Example 6-7. ISBN: 10: 0-13-507293-x