1/5+1/9+1/3=29/45
1/2 + 2/5 -2/3= 7/30
5/6 + 3/8-1/4=23/24
2^x+2^(x+3)=72
2^x*(1+2^3)=72
2^x*9=72
2^x=8
2^x=2^3
x=3
25/125*100=20%100/125*100=80%120/125*100=96%
1) 10 - х = 3 3/4
- x = 3 3/4+10
- x = 13 3/4
2) 3х - 5х - 7х = 23
- 9x = 23
- x = 23/9
x = - 2 5/9
3) 4/5 * ( х + 2 1/2 ) = 2/3 * ( 2х + 5 )
4/5 x + 4/2 = 4/3 x + 10/3
4/5 x - 4/3 x = 10/3 - 4/2
- 8/15 x = 8/6
x = 8/6 : ( - 8/15 )
x = 8/6 × ( - 15/8 )
x = - 15/6 *сокращаем на 3*
x = - 5/3
x = -2 1/3.
1) 3 + 3 = 6 (задач) решили
2) 8 - 6 = 2(задачи)
Ответ: 2 задачи осталось решить.