Math Problem Statement

Solve these simultaneous equations:

7y+2x= 11.5

5y+3x= 9

Solution

We are given the following system of simultaneous linear equations:

  1. 7y+2x=11.57y + 2x = 11.5
  2. 5y+3x=95y + 3x = 9

We can solve this system using the substitution or elimination method. Here, we'll use the elimination method.

Step 1: Eliminate one variable

To eliminate one variable, we can multiply each equation by appropriate constants so that the coefficients of one of the variables are the same. Let's eliminate xx by multiplying the first equation by 3 and the second equation by 2:

  • Multiply the first equation by 3: 3(7y+2x)=3(11.5)21y+6x=34.53(7y + 2x) = 3(11.5) \quad \Rightarrow \quad 21y + 6x = 34.5
  • Multiply the second equation by 2: 2(5y+3x)=2(9)10y+6x=182(5y + 3x) = 2(9) \quad \Rightarrow \quad 10y + 6x = 18

Step 2: Subtract the equations

Now, subtract the second equation from the first to eliminate xx:

(21y+6x)(10y+6x)=34.518(21y + 6x) - (10y + 6x) = 34.5 - 18

This simplifies to:

11y=16.511y = 16.5

Step 3: Solve for yy

y=16.511=1.5y = \frac{16.5}{11} = 1.5

Step 4: Substitute y=1.5y = 1.5 into one of the original equations

We can substitute y=1.5y = 1.5 into the first equation:

7(1.5)+2x=11.57(1.5) + 2x = 11.5 10.5+2x=11.510.5 + 2x = 11.5 2x=11.510.52x = 11.5 - 10.5 2x=12x = 1 x=12=0.5x = \frac{1}{2} = 0.5

Final Solution

The solution to the system of equations is: x=0.5,y=1.5x = 0.5, \quad y = 1.5

Would you like more details on any part of the process?

Related Questions:

  1. What are some other methods for solving simultaneous equations?
  2. How can you solve nonlinear systems of equations?
  3. Can graphing be used to solve this system of equations?
  4. How does the substitution method work in solving systems of equations?
  5. What is Cramer's rule, and how can it be applied to solve systems of equations?

Tip:

When solving simultaneous equations, it's helpful to choose the method (elimination, substitution, or graphical) that seems easiest based on the structure of the equations.

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Math Problem Analysis

Mathematical Concepts

Algebra
Simultaneous Equations
Linear Equations

Formulas

Elimination method: ax + by = c
Substitution method

Theorems

Properties of Linear Equations

Suitable Grade Level

Grades 8-10