Choose the two equations that have infinitely many solutions.

A.
3x+x=4x

B.
3(x+1)=3x+3

C.
2(x+1)=2x+1

D.
3(x+1)=3x+2

E.
2(x+2)=x+4

1 answer

To determine which equations have infinitely many solutions, we need to simplify each equation and check if they are equivalent (which means they have infinitely many solutions).

A. \( 3x + x = 4x \)

  • Simplifying: \( 4x = 4x \) → True for all \( x \) (infinitely many solutions)

B. \( 3(x + 1) = 3x + 3 \)

  • Simplifying: \( 3x + 3 = 3x + 3 \) → True for all \( x \) (infinitely many solutions)

C. \( 2(x + 1) = 2x + 1 \)

  • Simplifying: \( 2x + 2 = 2x + 1 \)
  • This reduces to: \( 2 = 1 \), which is a contradiction (no solutions)

D. \( 3(x + 1) = 3x + 2 \)

  • Simplifying: \( 3x + 3 = 3x + 2 \)
  • This reduces to: \( 3 = 2 \), which is a contradiction (no solutions)

E. \( 2(x + 2) = x + 4 \)

  • Simplifying: \( 2x + 4 = x + 4 \)
  • This reduces to: \( 2x = x \) → \( x = 0 \) (one solution, not infinitely many)

The equations with infinitely many solutions are:

  • A. \( 3x + x = 4x \)
  • B. \( 3(x + 1) = 3x + 3 \)

So, the correct answers are A and B.