tolong di bantu dong

3/√7 x √7/√7 = 3√7/7
√3/2√5 x 2√5/2√5 = 2√15/2.5 = 2√15/10 = 1/5√15
2/1+√5 x 1-√5/1-√5 = 2-2√5 / 1-5 = 2-2√5/-4 = -2√5/-2