Answer:
7
Step-by-step explanation:
Let c be the number of correct problems.
If there are 10 problems and c was the number of correct problems then 10-c is the number of incorrect problems.
The sum of correct problems and incorrect problems is equal to the number of problems in all.
Each correct question is worth +5 each.
Each incorrect question is worth -2 each.
The the total points she got was 29.
The equation we are solving is:
5c+-2(10-c)=29
Distribute:
5c+-20+2c=29
Combine like terms:
5c+2c-20=29
Simplify:
7c-20=29
Add 20 on both sides:
7c=49
Divide both sides by 7:
c=49/7
Simplify:
c=7
This means the person got 7 right and 3 wrong.
Checking:
Recall she gets 5 points per right answer and -2 points per wrong problem.
So 7(5) is what she gets for being right which is 35.
And -2(3) is what she gets for being wrong which is -6.
The total points there is 35+(-6)=29.
