I think this is more of an opinion question. What someone could solve mentally may not be the same as someone else's.If it were my worksheet, I'd circle all of them but it may be different for you.
At your level, I'd probably circle:
54 - 10
93 - 20
and 39 - 2
Answer:
The second one (B)
Step-by-step explanation:
u don't multiply a number by the same number if u know what I mean
hope this helps <3
We can distribute
2(5)+2(-x)=10-2x
we get
8+10-2x=?
18-2x=?
whatever that ? is, we don't know
multiply both sides by -1
2x-18=-?
add 18 to both sides
2x=18-?
divide bth sides by 2
x=9-(?/2)
whatever the left side it, just divide it by 2 and subtract it from 9