Answer is -7
Step-by-step explanation:
Draw a number line. Plot -3 on the number line. Then move 4 units to the left to go from -3 to -7
This is a visual way to see that -3-4 = -7
When we subtract a positive from a negative, we are basically adding the two positive versions of the number and making the final result negative. So we can think of it as 3+4 = 7, then make the 7 negative to get -7.
In terms of money, you can think of -3 as you are 3 dollars in debt. Tacking on the -4 means you go four more additional dollars in debt leading to a total debt of 3+4 = 7 dollars. Writing -7 means you are 7 dollars in debt when everything is said and done.