All Exams Test series for 1 year @ ₹349 only
Question

The system of equations x + 2y = 13 and 3x + 6y = 9 has:

The correct answer is

No solution

Understanding the System of Linear Equations

We are given a system of two linear equations with two variables, x and y:

  1. \(x + 2y = 13\)
  2. \(3x + 6y = 9\)

To determine the number of solutions for a system of linear equations in the form \(a_1x + b_1y = c_1\) and \(a_2x + b_2y = c_2\), we can compare the ratios of the coefficients and the constant terms.

For the given equations:

  • Equation 1: \(a_1 = 1\), \(b_1 = 2\), \(c_1 = 13\)
  • Equation 2: \(a_2 = 3\), \(b_2 = 6\), \(c_2 = 9\)

Now, let's calculate the ratios:

Ratio Calculation Value
\(a_1/a_2\) \(1/3\) \(1/3\)
\(b_1/b_2\) \(2/6\) \(1/3\)
\(c_1/c_2\) \(13/9\) \(13/9\)

We compare these ratios to determine the type of solution(s):

  • If \(a_1/a_2 \neq b_1/b_2\), there is a unique solution. The lines intersect at one point.
  • If \(a_1/a_2 = b_1/b_2 = c_1/c_2\), there are infinitely many solutions. The lines are coincident (the same line).
  • If \(a_1/a_2 = b_1/b_2 \neq c_1/c_2\), there is no solution. The lines are parallel and distinct.

In our case, we have:

\(a_1/a_2 = 1/3\)
\(b_1/b_2 = 1/3\)
\(c_1/c_2 = 13/9\)

Comparing these values, we see that \(a_1/a_2 = b_1/b_2\), but \(c_1/c_2\) is different. Specifically, \(1/3 = 1/3 \neq 13/9\).

This condition, \(a_1/a_2 = b_1/b_2 \neq c_1/c_2\), indicates that the system of equations has no solution.

Geometrically, the two equations represent two distinct parallel lines that never intersect.

Let's check this by trying to manipulate the equations. If we multiply the first equation (\(x + 2y = 13\)) by 3, we get \(3(x + 2y) = 3(13)\), which simplifies to \(3x + 6y = 39\).

Now we compare this with the second equation (\(3x + 6y = 9\)). We have two equations that state the same expression (\(3x + 6y\)) is equal to two different values (39 and 9). This is a contradiction, \(39 \neq 9\), which confirms that there is no pair of values (x, y) that can satisfy both equations simultaneously.

Therefore, the system of equations has no solution.

Was this answer helpful?

Important Questions from System of Linear Equations

  1. A system of equations is said to be inconsistent if

  2. If a system of simultaneous equations has infinite solutions, then that system of equations is called:

  3. Consider the system of simultaneous equation,

    x + 2y + z = 6

    2x + y + 2z = 6

    x + y + z = 5

    The system has,

  4. For what value of k, the system linear equation has no solution

    (3k + 1)x + 3y - 2 = 0

    (k2 + 1)x + (k - 2)y - 5 = 0

  5. The nine numbers x1, x2, x3 ... x9, are in ascending order. Their average m is strictly greater than all the first eight numbers. Which of the following is true?

Need Expert Advice?

Start Your Preparation with Prepp Mobile App

Download the app from Google Play & App Store
Download the app from Google Play & App Store
Prepp Mobile App