Solve for \( x \) and \( y \) simultanously (1) \( 3 x+2 y=7 \) and \( -3 x+y=1 \) (2) \( x+3 y=17 \) and \( 4 x-2 y=12 \) (3) \( x+2 y=13 \) and \( 3 x-y=4 \)
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The Deep Dive
Alright! Let's dive into solving these simultaneous equations! For the first set of equations: (1) \( 3x + 2y = 7 \) (2) \( -3x + y = 1 \) From equation (2), we can express \( y \): \[ y = 1 + 3x \] Now substitute this into equation (1): \[ 3x + 2(1 + 3x) = 7 \] \[ 3x + 2 + 6x = 7 \] \[ 9x + 2 = 7 \] \[ 9x = 5 \] \[ x = \frac{5}{9} \] Now substitute \( x \) back to find \( y \): \[ y = 1 + 3\left(\frac{5}{9}\right) = 1 + \frac{15}{9} = 1 + \frac{5}{3} = \frac{8}{3} \] So the solution is \( x = \frac{5}{9} \) and \( y = \frac{8}{3} \). --- For the second set of equations: (1) \( x + 3y = 17 \) (2) \( 4x - 2y = 12 \) From equation (1), solve for \( x \): \[ x = 17 - 3y \] Substitute this into equation (2): \[ 4(17 - 3y) - 2y = 12 \] \[ 68 - 12y - 2y = 12 \] \[ 68 - 14y = 12 \] \[ -14y = 12 - 68 \] \[ -14y = -56 \] \[ y = 4 \] Now substitute \( y \) back to find \( x \): \[ x = 17 - 3(4) = 17 - 12 = 5 \] So the solution is \( x = 5 \) and \( y = 4 \). --- For the third set of equations: (1) \( x + 2y = 13 \) (2) \( 3x - y = 4 \) From equation (1), solve for \( x \): \[ x = 13 - 2y \] Substituting this into equation (2): \[ 3(13 - 2y) - y = 4 \] \[ 39 - 6y - y = 4 \] \[ 39 - 7y = 4 \] \[ -7y = 4 - 39 \] \[ -7y = -35 \] \[ y = 5 \] Now substitute \( y \) back to find \( x \): \[ x = 13 - 2(5) = 13 - 10 = 3 \] So the solution is \( x = 3 \) and \( y = 5 \). ### Summary of Solutions: 1. \( x = \frac{5}{9}, y = \frac{8}{3} \) 2. \( x = 5, y = 4 \) 3. \( x = 3, y = 5 \)