Plz me with a and b
who can answer in a minute

How many different ways can you make change for $.50 using only nickels,dimes, and quarters?

What is (28 + 7 + 6 + 3) x 1/2 show your work

Me! 50 points! why does when we come home, our door is unlocked and there is grease on the door knob, me solve this , and i don't know what category this goes under