2x-3y/4=3 5x=2y+7 By Substitution Method

3 min read Jul 25, 2024
2x-3y/4=3 5x=2y+7 By Substitution Method

Solving Systems of Linear Equations: 2x - 3y/4 = 3 and 5x = 2y + 7 by Substitution Method

In this article, we will solve a system of linear equations using the substitution method. The system of equations is:

Equation 1: 2x - 3y/4 = 3 Equation 2: 5x = 2y + 7

Step 1: Solving Equation 2 for y

We can solve Equation 2 for y by rearranging the terms:

5x = 2y + 7

Subtracting 7 from both sides gives:

5x - 7 = 2y

Dividing both sides by 2 gives:

(5x - 7)/2 = y

Step 2: Substituting the expression for y into Equation 1

Now, we can substitute the expression for y into Equation 1:

2x - 3((5x - 7)/2)/4 = 3

Step 3: Simplifying the expression

Simplifying the expression, we get:

2x - 3(5x - 7)/8 = 3

Expanding the parentheses and combining like terms, we get:

2x - 15x/8 + 21/8 = 3

Step 4: Solving for x

Multiplying both sides by 8 to eliminate the fractions, we get:

16x - 15x + 21 = 24

Combining like terms, we get:

x + 21 = 24

Subtracting 21 from both sides gives:

x = 3

Step 5: Finding the value of y

Now that we have found the value of x, we can substitute it back into the expression for y:

y = (5x - 7)/2 = (5(3) - 7)/2 = (15 - 7)/2 = 8/2 = 4

Solution

Therefore, the solution to the system of linear equations is x = 3 and y = 4.

Verification

We can verify the solution by plugging the values back into both equations:

Equation 1: 2(3) - 3(4)/4 = 3 = 6 - 3 = 3 (True)

Equation 2: 5(3) = 2(4) + 7 = 15 = 15 (True)

The solution satisfies both equations, confirming that x = 3 and y = 4 is the correct solution.