Plz needs help QUICKLY

Kari wants to subtract 353 – 107 mentally.
Which of the following should she do first to find the difference?
A.

Add 3 to 107 and add 3 to 353.
B.

Add 3 to 107 and subtract 3 from 353.
C.

Subtract 7 from 107 and subtract 3 from 353.
D.

Subtract 7 from 107 and add 7 to 353.

The answer would be D.

Step-by-step explanation:

Subtracting 7 from 107 would make it 100. Adding that 7 to 353 would make in 360. It is easier to do 360 - 100 in your head.

C

Step-by-step explanation:

When you subtract 7 from 107, it would be 100 and when you subtract 3 from 353 it would be 350 so : 350 - 100. That’s much easier!

Hope this helped!

option (b) is correct

step-by-step explanation:

to find the solution of this system, we need to convert it into reduced row-echelon form. we have,

after applying row operations r2 -> r2/2 and r3 -> r3/3, we get,