2. Упростить: √27 - √12 + √75; 0,7√45 + (1/2)√20

**√27 - √12 + √75:** √27 = √(9 * 3) = 3√3 √12 = √(4 * 3) = 2√3 √75 = √(25 * 3) = 5√3 3√3 - 2√3 + 5√3 = (3 - 2 + 5)√3 = 6√3 **0,7√45 + (1/2)√20:** 0,7√45 = 0,7 * √(9 * 5) = 0,7 * 3√5 = 2,1√5 (1/2)√20 = (1/2) * √(4 * 5) = (1/2) * 2√5 = √5 2,1√5 + √5 = 3,1√5