Respuesta :

−2.8
Okay so "0.9x-1.3=-3.1" x=-2
 
0.9x−1.3=−3.1

add 1.3 to both sides

0.9x−1.3+1.3=−3.1+1.3

0.9x=−1.8

divide both sides by 0.9

0.9x/0.9=−1.8/0.9

x=−2

So if you plug in -2 into "x-0.8" you get −2.8

=−2−0.8

=−2-0.8

=−2.8

Hope this helps. 
Your answer is -2.8.