Question

как можно скорее
2x-(1+9x)=20

Answer 1

2x-(1+9x)=20

2x-1-9x=20

7х= - 21

х= -21/7= - 3

Answer 2

2x-(1+9x)=20
2x-1-9x=20
-7x=21
x=21÷(-7)
x=-3