1)9 1/2 ÷(1 4/7 - 5/21 ×0,9)19/2 ÷ (11/7 - 5/21 × 9/10)19/2 ÷ (11/7 - 1/7 × 3/2 )19/2 ÷ (11/7 - 3/14 )19/2 ÷ 19/1419/2 × 14/19 =7
2)
(p-4q)(2p+q)-29×14=-406.
x+y/5y = 4/10 =2/5.
3)-
4)
(8x+6)-(7x+4)=5
8x+6-7x-4=5
x+2=5
x=5-2
x=3.
5)
0,5 (x+3)=0,4 (x-6)+7,7
0,5x+1,5=0,4x-2,4+7,7
0,5x+1,5=0,4x+5,3
0,5x-0,4x=5,3-1,5
0,1x=3,8
x=38.