Question

Which equation has the solution x = 3?

Select each correct answer.



9x−1=4

9 over x end fraction minus 1 equals 4

3x + 1 = 9

3, x, + 1 = 9

2x + 4 = 10

2, x, + 4 = 10

5x−7=1

5 x minus 7 equals 1

x3+5=6

x over 3 end fraction plus 5 equals 6

9−3x=0

Answer 1

• 2x +4 = 10
• x/3 +5 = 6

Explanation:

You want to know which of several equations have x=3 as a solution. The equations are ...

• 9/x -1 = 4
• 3x +1 = 9
• 2x +4 = 10
• 5x -7 = 1
• x/3 +5 = 6

Substitution

The value x=3 will be a solution if it satisfies the equation. Substituting that value into the given equations, we find ...

• 9/3 -1 = 2 ≠ 4
• 3(3) +1 = 10 ≠ 9
• 2(3) +4 = 10
• 5(3) -7 = 8 ≠ 1
• 3/3 +5 = 6

The value x = 3 is a solution to ...

• 2x +4 = 10
• x/3 +5 = 6