Question

Решите уравнение: 1)0,9х-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)

Answer 1

1)0.9х-0.6х+1.8=0.4х-2.6
0.3х+1.8=0.4х-2.6
0.4х-0.3х=1.8+2.6
0.1х=4.4
х=4.4÷0.1
х=44

2)
-1.2х+0.4+6.4х-2.4=5-3.8х-4
5.2х-2=1-3.8х
5.2х+3.8х=1+2
9х=3
х=3÷9
х=1/3

3)
4/7(56/100-4 2/10у)+4/10=
=5/13(52/100-6 5/10у)
4/7(14/25-4 1/5у)+2/5=
=5/13(13/25-6 1/2у)
4/7(14/25-21/5у)+2/5=
=5/13(13/25-13/2у)
8/25-12/5у+2/5=1/5-5/2у
-12/5у+5/2у=1/5-8/25-2/5
-24/10у+25/10у=5/25-8/25-10/25
1/10у=-13/25
у=-13/25÷1/10
у=-13/25×10/1
у=-26/5=-5 1/5

Answer 2

спасибо огромное!