Math Problem Statement

How many solutions does the system of equations below have?

5x − 10y = 9 –3x + 16y = 5

Solution

We are given the system of equations:

5x - 10y = 9 \tag{1} -3x + 16y = 5 \tag{2}

To determine how many solutions this system has, we can use the method of substitution or elimination.

Let's use elimination to solve this.

Step 1: Multiply the equations to align the coefficients of xx or yy

We want to eliminate one of the variables by making their coefficients equal. Let's eliminate xx.

  • Multiply equation (1) by 3 and equation (2) by 5 so the coefficients of xx will become equal (but with opposite signs):

3(5x - 10y) = 3(9) \quad \Rightarrow \quad 15x - 30y = 27 \tag{3} 5(-3x + 16y) = 5(5) \quad \Rightarrow \quad -15x + 80y = 25 \tag{4}

Step 2: Add the two new equations

Now, add equations (3) and (4) together to eliminate xx:

(15x30y)+(15x+80y)=27+25(15x - 30y) + (-15x + 80y) = 27 + 25 0x+50y=520x + 50y = 52 50y=5250y = 52 y=5250=2625y = \frac{52}{50} = \frac{26}{25}

Step 3: Substitute y=2625y = \frac{26}{25} into one of the original equations

Now that we know yy, we can substitute it back into one of the original equations to solve for xx. Using equation (1):

5x10(2625)=95x - 10\left(\frac{26}{25}\right) = 9 5x26025=95x - \frac{260}{25} = 9 5x10.4=95x - 10.4 = 9 5x=9+10.45x = 9 + 10.4 5x=19.45x = 19.4 x=19.45=3.88x = \frac{19.4}{5} = 3.88

Conclusion:

The system has one solution, which is approximately x=3.88x = 3.88 and y=26251.04y = \frac{26}{25} \approx 1.04.

Would you like me to go into more details or clarify anything further?


Here are 5 related questions you might find interesting:

  1. How do you solve a system of equations using substitution?
  2. What is the significance of having exactly one solution for a system of linear equations?
  3. How do you recognize if a system of equations has no solution or infinitely many solutions?
  4. Can you solve a system of equations using matrices?
  5. What is the geometric interpretation of the solution to a system of two linear equations?

Tip: If you ever get stuck in the elimination method, try multiplying the equations by factors that simplify the coefficients and ensure they will cancel out when added or subtracted.

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Math Problem Analysis

Mathematical Concepts

Systems of Linear Equations
Elimination Method
Substitution Method

Formulas

Elimination method
Substitution method

Theorems

Linear Systems Theory

Suitable Grade Level

Grades 8-10