A) <span>-3.1a + 2.25b - a - 1.4b + 6.3a = 2,2а +0,85b
</span>b) <span>3/8(2,4х-3,2у)-1,8(5/9х+1,5у) =3/8 * 12/5x - 3/8 * 16/5у - 9/5 * 5/9х - 9/5 * 3/2у = 9/10х - 6/5у - х - 27/10у = -1/10х -39/10у =-0,1х - 3,9у</span>
44-48:((4*x):18-3)=20
48:((4*x):18-3)=44-20
48:((4*x):18-3)=24
(4*x):18-3=48:24
(4*x):18-3=2
(4*x):18=2+3
(4*x):18=5
4x=5*18
4x=90
x=90:4
x=22,5
360 : 50 = 7 10/50 = 7 2/10 = 7,2
1.30
2.33
3.77
4.70
5.73
6.37
7.307
8.370
9.703
10.337
11.377