40 = x - 20
move -20 to the other side
sign changes from -20 to +20
40+20= x-20+20
40+20=x
60=x
Answer:
b 60
if you mean 90 × 10⁴
then the answer would be, 900000.
but if you mean 9 × 10⁴ then the answer would be, 90000.
hope it helps.
Bye.
Not really, is this a rhetorical question? lol
Hey there!
Basically it wants you to add 3 and 8 from each other, what ever the answer to that part, you multiply the result by 9
Here this is what i meant

Or you could do this method too!

They both give you the result of 
So, I am assuming your expression would look like this: 
Good luck on your assignment and enjoy your day!
~