1) 0.9-0.6(х-3)=2(0.2х-1.3) 2) -0.4(3х-1)+8(0.8х-0.3)=5-(3.8х+4) - вопрос №416766810906320213204318080353843470 от mama791 12.02.2021 12:55

Question

Алгебра: 1) 0.9-0.6(х-3)=2(0.2х-1.3) 2) -0.4(3х-1)+8(0.8х-0.3)=5-(3.8х+4) 3) 4/7(0.56-4.2у)+0.4=5/13(0.52-6.5у)

mama791 · Answer

1)0.9-0.6х+1.8=0.4х-2.6 -0.6х-0.4х=-2.6-0.9-1.8
-х=-5.3 /•(-1)
х=5.3
2)-1.2х+0.4+6.4х-2.4=19х+20
-1.2х+6.4х-19х=20-0.4+2.4
5.2х=22
х=4.2

3)4/3.92-29.4у+0.4=5/6.76-84.5у
29.4у+84.5у=0.7-1-0.4
113.9у=-0.7
у=0.006