Final answer:
To solve a system of equations by substitution, you replace the variables with their given values and then determine if the resulting equation is true. For the given pairs (a, b, c, d), you would substitute the x and y values in an equation like y = 3x + 1 to see if they satisfy the equation, which they do not in these cases.
Step-by-step explanation:
To use substitution to solve the system of equations, you need to substitute variables with the given values.
Let’s consider the examples provided:
- For a) x = 1, y = 2: If you have an equation like y = 3x + 1, substitute x with 1 to get y = 3(1) + 1, which simplifies to y = 4. Since the given value for y is 2, this would not be the correct solution for that equation.
- For b) x = 2, y = 1: y = 3x + 1 becomes y = 3(2) + 1, which simplifies to y = 7. Since the given value for y is 1, this also would not be the correct solution.
- For c) x = 3, y = 4: y = 3x + 1 becomes y = 3(3) + 1, which simplifies to y = 10. The given value for y is 4, thus not a solution for this equation.
- For d) x = 4, y = 3: y = 3x + 1 becomes y = 3(4) + 1, simplifying to y = 13. The given value for y is 3, which again is not a solution for the equation.
In general, to solve equations using substitution, choose a value for the independent variable, and then solve for the dependent variable.