So start with R8 and R10, which are in series. You will get a combined resistance of 12 Ohms. Then, this combined 12 Ohm resistor is in parallel with the R9 resistor, and using the parallel resistors formula, you will get a combined resistance of 4 Ohms. Then, that last 4 Ohm resistor will be in series with R7, an 8 Ohm resistor, so 4 + 8 = 12 Ohms. Then, this last 12 Ohm resistor will be parallel to resistor R6. Again, use the parallel resistors formula and you will again get a combined resistor of 4 Ohms. Then, this 4 Ohm resistor will be in series with the R5 resistor (with 4 Ohms), giving a combined resistor of 8 Ohms. Then, this 8 Ohm resistor will be in parallel with the R4 resistor, which is also 8 Ohms. Using the parallel resistors formula again, you get 4 Ohms. Then, this 4 Ohm resistor will be in series with the R3 resistor, which is also 4 Ohms. Using the series resistors formula, you will get 8 Ohms, and then this 8 Ohm resistor will be in parallel with the last 8 Ohm resistor, which is R2. Use the parallel resistor formula again and you will get a combined resistance of 4 Ohms. Finally, there is a simple loop and you can just add the last 4 Ohm resistor you calculated with R1, which is 6 Ohms, giving you a final Req of 10 Ohms.
So start with R8 and R10, which are in series. You will get a combined resistance of 12 Ohms. Then, this combined 12 Ohm resistor is in parallel with the R9 resistor, and using the parallel resistors formula, you will get a combined resistance of 4 Ohms. Then, that last 4 Ohm resistor will be in series with R7, an 8 Ohm resistor, so 4 + 8 = 12 Ohms. Then, this last 12 Ohm resistor will be parallel to resistor R6. Again, use the parallel resistors formula and you will again get a combined resistor of 4 Ohms. Then, this 4 Ohm resistor will be in series with the R5 resistor (with 4 Ohms), giving a combined resistor of 8 Ohms. Then, this 8 Ohm resistor will be in parallel with the R4 resistor, which is also 8 Ohms. Using the parallel resistors formula again, you get 4 Ohms. Then, this 4 Ohm resistor will be in series with the R3 resistor, which is also 4 Ohms. Using the series resistors formula, you will get 8 Ohms, and then this 8 Ohm resistor will be in parallel with the last 8 Ohm resistor, which is R2. Use the parallel resistor formula again and you will get a combined resistance of 4 Ohms. Finally, there is a simple loop and you can just add the last 4 Ohm resistor you calculated with R1, which is 6 Ohms, giving you a final Req of 10 Ohms.