1)
1. -1 1/10÷1/20+14 2/7×(-14)=- 11/10×20/1+100/7×(-14)=
=-22-200=-222
2. 7,2÷0,08+(-3,9)÷(-13)=90+0,3=90,3
2.49÷7×8=56 машин было на стоянке
3. (x+12)(x-11)=0
x+12=0 x=0-12=-12
x-11=0 x=0+11=11
x=-12
x=11
4. L=2×3,14×2,9=18,22см
S=3,14×2,9×2,9=26,42см²
5. 2 1/9÷2 4/9=7,6÷x
2 1/9x=2 4/9×7,6
19/9x=22/9×38/5
19/9x=836/45
x=836/45÷19/9=836/45×9/19
x=44/5=8 4/5 =8,8
6. 209,290,902,920
