Diagnostic

Systems of Equations and Inequalities

Match each system on the left with the number of solutions it has on the right. Answer options on the right may be used more than once.

[tex]\[
\begin{array}{l}
1.\ x = y - 3 \\
\ \ \ \ 2x - 2y = -6 \\
2.\ 5x + 2y = -7 \\
\ \ \ \ 15x + 6y = 21 \\
3.\ y = 2x + 1 \\
\ \ \ \ 2x - y = 1 \\
4.\ 6x + 4y = 10 \\
\ \ \ \ 3x + 2y = 5
\end{array}
\][/tex]

Answer Options:

- No solution
- One solution
- Infinite number of solutions

Click and hold an item in one column, then drag it to the matching item in the other column.



Answer :

Certainly! Let's analyze each system of equations step-by-step to determine the number of solutions.

### System 1: [tex]\( x = y - 3 \)[/tex] and [tex]\( 2x - 2y = -6 \)[/tex]

1. Substitute [tex]\( x = y - 3 \)[/tex] into [tex]\( 2x - 2y = -6 \)[/tex]:
[tex]\[ 2(y - 3) - 2y = -6 \][/tex]
Simplify:
[tex]\[ 2y - 6 - 2y = -6 \][/tex]
[tex]\[ -6 = -6 \][/tex]

The equation simplifies to a true statement [tex]\((-6 = -6\)[/tex]), which means there are infinitely many solutions. The two equations are dependent, describing the same line.

Result: Infinite number of solutions

### System 2: [tex]\( 5x + 2y = -7 \)[/tex] and [tex]\( 15x + 6y = 21 \)[/tex]

1. Notice that the second equation is a multiple of the first equation:
[tex]\[ 15x + 6y = 21 \quad \text{(Triple the first equation} \rightarrow 3(5x + 2y) = 3(-7) = -21\text{)} \][/tex]
[tex]\[ 15x + 6y \neq -21 \][/tex]

The second equation simplifies to [tex]\( 15x + 6y = -21 \)[/tex], indicating a contradiction [tex]\( (21 \neq -21) \)[/tex].

Result: No solution

### System 3: [tex]\( y = 2x + 1 \)[/tex] and [tex]\( 2x - y = 1 \)[/tex]

1. Substitute [tex]\( y = 2x + 1 \)[/tex] into [tex]\( 2x - y = 1 \)[/tex]:
[tex]\[ 2x - (2x + 1) = 1 \][/tex]
Simplify:
[tex]\[ 2x - 2x - 1 = 1 \][/tex]
[tex]\[ -1 = 1 \][/tex]

Since [tex]\( -1 \neq 1 \)[/tex], we see a contradiction, implying that no values of [tex]\( x \)[/tex] and [tex]\( y \)[/tex] satisfy both equations simultaneously.

Result: No solution

### System 4: [tex]\( 6x + 4y = 10 \)[/tex] and [tex]\( 3x + 2y = 5 \)[/tex]

1. Notice that the second equation is a multiple of the first equation:
[tex]\[ 6x + 4y = 10 \quad ( \text{Double the second equation} \rightarrow 2(3x + 2y) = 2(5) = 10) \][/tex]
[tex]\[ 6x + 4y = 10 \][/tex]

Both equations represent the same line, which means every point on this line is a solution.

Result: Infinite number of solutions

In summary:

- System 1: Infinite number of solutions
- System 2: No solution
- System 3: No solution
- System 4: Infinite number of solutions