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Solve by cross - multiplication : 2x +...

Solve by cross - multiplication :
`2x + 3y = 6 and 6x - 5y = 4`.

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To solve the given simultaneous equations using the cross-multiplication method, we have the equations: 1. \( 2x + 3y = 6 \) (Equation 1) 2. \( 6x - 5y = 4 \) (Equation 2) ### Step 1: Write the equations in standard form The equations are already in standard form, which is \( Ax + By = C \). ### Step 2: Identify coefficients From the equations, we can identify the coefficients: - For Equation 1: \( A_1 = 2, B_1 = 3, C_1 = 6 \) - For Equation 2: \( A_2 = 6, B_2 = -5, C_2 = 4 \) ### Step 3: Set up the cross-multiplication Using the cross-multiplication method, we set up the following ratios: \[ \frac{x}{B_1C_2 - B_2C_1} = \frac{y}{A_2C_1 - A_1C_2} = \frac{1}{A_1B_2 - A_2B_1} \] ### Step 4: Calculate the determinants 1. Calculate \( B_1C_2 - B_2C_1 \): \[ B_1C_2 - B_2C_1 = 3 \cdot 4 - (-5) \cdot 6 = 12 + 30 = 42 \] 2. Calculate \( A_2C_1 - A_1C_2 \): \[ A_2C_1 - A_1C_2 = 6 \cdot 6 - 2 \cdot 4 = 36 - 8 = 28 \] 3. Calculate \( A_1B_2 - A_2B_1 \): \[ A_1B_2 - A_2B_1 = 2 \cdot (-5) - 6 \cdot 3 = -10 - 18 = -28 \] ### Step 5: Substitute into the ratios Now we have: \[ \frac{x}{42} = \frac{y}{28} = \frac{1}{-28} \] ### Step 6: Solve for \( x \) and \( y \) From the first ratio: \[ x = 42 \cdot \frac{1}{-28} = -\frac{42}{28} = -\frac{3}{2} \] From the second ratio: \[ y = 28 \cdot \frac{1}{-28} = -1 \] ### Final Result Thus, the solution to the simultaneous equations is: \[ x = -\frac{3}{2}, \quad y = -1 \]
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