1) 0,3х+0,8у+1,5х+1,2у=1,8х+2у

2) 4,2х+5,3у-2,6у-1,8х=2,4х+2,7у

3) 1,5a+9,7b+5,8а-1,3b=7,3а+8,4b

4) 12,75а+1,85b-9,55а+3,5b=3,2а+5,35b

Ответ:

1)x(0.3+1.5)+y(0.8+1.2)=1.8x+2y

3)x(4.2-1.8)+y(5.3-2.6)=2.4x+2.7y

4)a(1.5+5.8)+b(9.7-1.3)=7.3a+8.4b

5)a(12.75-9.55)+b(1.85+3.5)=3.2a+5.35b