Solve the following pair of equations by substitution method: 7x−15y=27x - 15y = 2 (1) and x+2y=3x + 2y = 3 (2).

Answer: The solution to the system of equations is x=4929x = \frac{49}{29} and y=1929y = \frac{19}{29}.

Step-by-step solution

Step 1: Express one variable in terms of the other

From equation (2), we can easily express xx in terms of yy. This is the first step in the substitution method, as outlined in the NCERT textbook. We move the 2y2y term to the right side of the equation.

Step 2: Substitute the expression into the other equation

Now, we substitute the expression for xx (3−2y3 - 2y) from the first step into equation (1). This will give us a linear equation in a single variable, yy, which we can then solve.

Step 3: Simplify and solve for y

We distribute the 7, combine like terms, and then isolate yy. We subtract 21 from both sides and then divide by -29 to find the value of yy.

Step 4: Substitute the value of y back into the expression for x

Now that we have the value of yy, we substitute it back into the expression for xx we found in the first step. This allows us to calculate the value of xx. We perform the multiplication and then find a common denominator to subtract the fractions.

Step 5: Verify the solution

We check if the calculated values of xx and yy satisfy both original equations. By plugging in x=4929x = \frac{49}{29} and y=1929y = \frac{19}{29} into equations (1) and (2), we confirm that both equations hold true, validating our solution.

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