Math Problem Statement

Solvethefollowingsystemof linearequationsbysubstitution i. 1/2m+1/3n =3 1/4m - 2/3n = -1

Solution

Let's solve the system of linear equations using the substitution method:

Given the system:

  1. 12m+13n=3\frac{1}{2}m + \frac{1}{3}n = 3
  2. 14m23n=1\frac{1}{4}m - \frac{2}{3}n = -1

Step 1: Solve one equation for one variable

Let's start with the first equation and solve for mm in terms of nn:

12m+13n=3\frac{1}{2}m + \frac{1}{3}n = 3

Subtract 13n\frac{1}{3}n from both sides:

12m=313n\frac{1}{2}m = 3 - \frac{1}{3}n

Now, multiply both sides of the equation by 2 to isolate mm:

m=2(313n)m = 2\left(3 - \frac{1}{3}n\right)

Distribute the 2:

m=623nm = 6 - \frac{2}{3}n

Step 2: Substitute this expression for mm into the second equation

Now that we have m=623nm = 6 - \frac{2}{3}n, we substitute this into the second equation:

14m23n=1\frac{1}{4}m - \frac{2}{3}n = -1

Substitute m=623nm = 6 - \frac{2}{3}n:

14(623n)23n=1\frac{1}{4}(6 - \frac{2}{3}n) - \frac{2}{3}n = -1

Now, distribute 14\frac{1}{4} on the first term:

14(6)14×23n23n=1\frac{1}{4}(6) - \frac{1}{4} \times \frac{2}{3}n - \frac{2}{3}n = -1

3216n23n=1\frac{3}{2} - \frac{1}{6}n - \frac{2}{3}n = -1

Step 3: Combine like terms

To combine the nn-terms, we need a common denominator. The least common denominator between 6 and 3 is 6, so rewrite 23n\frac{2}{3}n as 46n\frac{4}{6}n:

3216n46n=1\frac{3}{2} - \frac{1}{6}n - \frac{4}{6}n = -1

Combine the nn-terms:

3256n=1\frac{3}{2} - \frac{5}{6}n = -1

Step 4: Solve for nn

First, subtract 32\frac{3}{2} from both sides:

56n=132-\frac{5}{6}n = -1 - \frac{3}{2}

Convert 1-1 to 22-\frac{2}{2}:

56n=2232=52-\frac{5}{6}n = -\frac{2}{2} - \frac{3}{2} = -\frac{5}{2}

Now, multiply both sides by 65-\frac{6}{5} to isolate nn:

n=(52)×(65)n = \left(-\frac{5}{2}\right) \times \left(-\frac{6}{5}\right)

n=3n = 3

Step 5: Substitute n=3n = 3 back into the equation for mm

Now that we know n=3n = 3, substitute this value into the expression for mm:

m=623(3)m = 6 - \frac{2}{3}(3)

m=62m = 6 - 2

m=4m = 4

Final Answer:

The solution to the system of equations is:

m=4,n=3m = 4, \quad n = 3


Would you like a more detailed explanation of any step or help with another topic?

Here are 5 related questions for further exploration:

  1. How can you solve a system of equations by elimination?
  2. What if the system of equations had no solution or infinite solutions?
  3. How does graphing relate to solving systems of linear equations?
  4. How do you use substitution with a fractional coefficient?
  5. What are some common mistakes to avoid when solving by substitution?

Tip: When working with fractions, always try to clear the fractions early by multiplying both sides of an equation by the least common denominator (LCD).

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Math Problem Analysis

Mathematical Concepts

Linear Equations
Substitution Method

Formulas

Substitution method for solving systems of equations

Theorems

Substitution method for solving linear systems

Suitable Grade Level

Grades 8-10