can u explain how we got (i) IN DETAILS PLEASE

Year DDB TI CFBT -50000 Tax = TI * TCFAT = CFBT - TAX -50000 0 1 10000 -4000 14000 2. 14000 800 3 18000 22000 20000-10000 12000 2000 7200 10800 4320 17680 2592 23408 13200 13680 14928 16637 4320 7072 9363 4 5 26000 (a) Before Tax Internal Rate of Return NPW = -50000+10000(PIA, 1,5) + 4000((P/G, 1, 5) = 0 We solve the above equation we get i = 19.6% (b) After Tax Internal Rate of Return NPW = -50000+14000(P/F, 1, 1) + 13200(P/F, 1, 2) + 13680(P/F.1,3) + 14928(P/F, 1, 4)+ 16637(P/F, 1,5) = 0 We solve the above equation we get i = 13.3% 12