Barb had $55 in her checking account. She spent $12 on makeup and $13 on socks. How much is in her checking account now?

Barb now has 30$ left.

Step-by-step explanation:

55-12=43 43-13=30

a. she will receive a refund of $278.

step-by-step explanation:

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,