1) √1,8 * √7/9 *√5 3/5 = √(0,2*9) * √7/9 *√28/5 =
√9 * √7*√28 √7*√7*√4
= √0,2 * √9 * √5 = √1/5 * √5 =
√1 * 7 * 2 14
= √5 * √5 = 5 = 2,8
2) √1 3/8 * √5 1/2 - √ (12,5² - 3,5²)/ 2*128 =
√11/8 * √11/2 - √ (12,5² - 3,5²) = √11 *√11 √ (12,5 - 3,5)(12,5+ 3,5) =
√ 2*128 √8*√2 * √ 2*√2*√64
11 √ 9 *√ 16 11 * 3 *4 33 1
= √4*√2*√2 * 2*8 = 2 * 2 * 16 = 16 = 2 16