Consider the equation 7x − 6 + 3 = 5x + 2x + 5.

Question 1
Which BEST describes the number of solutions for the given equation?
Responses
one solutionone solution
B two solutionstwo solutions
C infinitely many solutionsinfinitely many solutions
D no solutionno solution
Question 2
Which equation has infinitely many solutions?
Responses
A 9x − 3 = 3x + 6x + 2 + 39x − 3 = 3x + 6x + 2 + 3
B 12(x + 8) = 11x − 512(x + 8) = 11x − 5
C 11x − 2x + 15 = 8 + 7 + 9x11x − 2x + 15 = 8 + 7 + 9x
D 5x − 8 = 11 − 7x + 12x

1 answer

Let's analyze the questions one at a time.

Question 1: We need to find the number of solutions for the equation \( 7x - 6 + 3 = 5x + 2x + 5 \).

First, simplify both sides of the equation:

  1. Left side:
    \( 7x - 6 + 3 = 7x - 3 \)

  2. Right side:
    \( 5x + 2x + 5 = 7x + 5 \)

This gives us the equation:

\[ 7x - 3 = 7x + 5 \]

Now, let's bring all terms involving \( x \) to one side and constants to the other:

Subtract \( 7x \) from both sides:

\[ -3 = 5 \]

Since \(-3\) does not equal \(5\), the equation is a contradiction, meaning there are no solutions for the given equation.

Answer to Question 1: D) no solution

Question 2: We need to find which of the following equations has infinitely many solutions. An equation has infinitely many solutions if it can be simplified to the form \( 0 = 0 \).

Let's evaluate each option:

A) \( 9x − 3 = 3x + 6x + 2 + 3 \)
Simplifying the right side:
\( 3x + 6x + 2 + 3 = 9x + 5 \)
The equation becomes:
\( 9x - 3 = 9x + 5 \)
This simplifies to \(-3 = 5\), which is not true. No solution.

B) \( 12(x + 8) = 11x - 5 \)
Expanding the left side:
\( 12x + 96 = 11x - 5 \)
Moving terms gives us:
\( 12x - 11x = -5 - 96 \) → \( x = -101 \). One solution.

C) \( 11x - 2x + 15 = 8 + 7 + 9x \)
Simplifying both sides:
Left side: \( 9x + 15 \)
Right side: \( 15 + 9x \)
This simplifies to \( 9x + 15 = 9x + 15 \), which is always true. Infinitely many solutions.

D) \( 5x − 8 = 11 − 7x + 12x \)
Simplifying the right side: \( 5x - 8 = 11 + 5x \)
Moving terms gives us:
\( -8 = 11\), which is not true. No solution.

Answer to Question 2: C) \( 11x - 2x + 15 = 8 + 7 + 9x \) has infinitely many solutions.