Answer:
w= 8,1
Step by step:
w/9= 0.9
the 9, instead of dividing in becomes a multiplication, which you will multiply with 0.9, which is the answer
which goes like...
w/9 = 0.9
w = 0.9 x 9 = 8,1
And then we check it if it's true
8,1 / 9 = 0.9
And it is
