1) 20 * 5 : 1 = 100
2)40 * 3 : 1 = 120
3)50 * 6 : 1 = 300
4)30 * 2 : 1 = 60
5) 50* 4 : 1 = 200
6) 40 * 8 = 320
1.8 : (-2) - 5
9/5 : (-2)-5
- 9/5 * 1/2 - 5
- 9/10 - 5
- 59/10= - 5 9/10 = -5.9
1. S = πR²
R = √(S/π) = √(50,24/3,14) = √(16) = 4 см.
C = 2πR = 2*3,14*4 = 25,12 см = 2,512 дм ≈ 2,5 дм.
2. 1) R = √(25π/π) = √(25) = 5 дм
C = 2πR = 2*3,14*5 = 31,4 дм.
2) R = √(314/3,14) = √(100) = 10 см.
C = 2*3,14*10 = 62,8 см.