Use substitution to solve the system 3x 4y 3 y 2x 13 Sol

Use substitution to solve the system. 3x + 4y = - 3 y = 2x+ 13

3x + 4y = -3 -------------------- equation 1

y = 2x + 13 ----------------- equation 2

substituting value of y from equation 2 to equation 1

3x + 4( 2x + 13 ) = -3

3x + 8x + 52 = -3

11x + 52 = -3

subtracting 52 from both sides

11x = -3 - 52

11x = -55

dividing both sides by 11

x = - 5

plug x = - 5 in equation 2

y = 2x + 13

y = 2(-5) + 13 = 3

y = 3