1. The substitution method is used to solve systems of equations by expressing one variable in terms of the other and substituting it into the other equation. 2. Since the user mentioned "for the number 1," let's consider a system where we use substitution to find the variable equal to 1. 3. Suppose we have the system: $$x + y = 3$$ $$2x - y = 1$$ 4. Step 1: Solve the first equation for $y$: $$y = 3 - x$$ 5. Step 2: Substitute $y = 3 - x$ into the second equation: $$2x - (3 - x) = 1$$ 6. Step 3: Simplify and solve for $x$: $$2x - 3 + x = 1$$ $$3x - 3 = 1$$ $$3x = 4$$ $$x = \frac{4}{3}$$ 7. Step 4: Substitute $x = \frac{4}{3}$ back into $y = 3 - x$: $$y = 3 - \frac{4}{3} = \frac{9}{3} - \frac{4}{3} = \frac{5}{3}$$ 8. So, the solution to the system is $x = \frac{4}{3}$ and $y = \frac{5}{3}$. 9. Note: If you wanted $x$ or $y$ to be $1$, you can similarly substitute that value and solve using substitution method.