Question

Решите уравнения, . 8(y-7)-3(2y+9)=15; 0.6-0.5(y-1)=y+0.5; 0.15(x-4)=9.9-0.3(x-1); 3(3x-1)+2=5(1-2x)-1.

Answer 1

1)8(y-7)-3(2y+9)=15
8y-56-6y-27=15
8y-6y=15+56+27
2y=98
y=$\frac{2}{98} = \frac{1}{49}$

2)0.6-0.5(y-1)=y+0.5
0,6-0,5y+0,5=y+0,5
-0,5y-у=0,5-0,6-0,5
-1.5y=-0.6
y=2.5
ответ:y=2.5
3)0.15(x-4)=9.9-0.3(x-1)
0.15x-0.6=9.9-0.3x+0.3
0.15x+0.3x=9.9+0.3+0.6
0.45x=10.8
x=$\frac{0,45}{10,8}$

3(3x-1)+2=5(1-2x)-1
9x-3+2=5-10x-1
9x+10x=5-1+3-2
19x=11
x=$1 \frac{8}{11}$