The goal of this problem is to determine all of the equations where x = 3 is a solution and this can be done by simply inputting the value 3 into any variable x that is seen into the expression. After, inputting the value we would simplify both sides and compare them. If the expression evaluates to true then x = 3 is a solution of the equation but if it evaluates to false then x = 3 is not a solution of the equation.
Equation #1
After inputting the value 3 into x, we added 4 to it and the final result that we got on the left side was 7 which was equal to the right side (7). Therefore, x = 3 is a solution of the first equation.
Equation #2
After inputting the value 3 into x, we did 3 divided by 9 and the final result that we got on the left side was 1/3 which was not equal to the right side (3). Therefore, x = 3 is not a solution of the second equation.
Equation #3
After inputting the value 3 into x, we subtracted 3 from 5 and the final result that we got on the left side was 2 which was equal to the right side (2). Therefore, x = 3 is a solution of the third equation.
Equation #4
After inputting the value 3 into x, we multiplied 3 by 8 and the final result that we got on the left side was 24 which was not equal to the right side (32). Therefore, x = 3 is not a solution of the fourth equation.
Equation #5
After inputting the value 3 into x, we subtracted 10 from 3 and the final result that we got on the left side was -7 which was not equal to the right side (7). Therefore, x = 3 is not a solution of the fifth equation.
Therefore, the only expressions that had a solution of x = 3 was the first and third equations since the final expression evaluated to true.