S2A Chapter 4 Simultaneous Equations
2009 Chung Tai Educational Press. All rights reserved. © Simultaneous Linear Equations in Two Unknowns ( 1) 2(2) 3 ( 1) 3(2) 7 x 1 and y 2 is the solution of the simultaneous equations. are simultaneous linear equations in two unknowns
2009 Chung Tai Educational Press. All rights reserved. © Graphical Method The coordinates of the point of intersection is the solution of the simultaneous linear equations in two unknowns. In the graph, two straight lines intersect at ( 1, 2). The solution of the simultaneous equations is x 1, y 2. x 3y 7 x 2y 3
2009 Chung Tai Educational Press. All rights reserved. © From (1), x 3 2y (3) Substitute (3) into (2), 3 – 2y – 3y 7 5y 10 y 2 Substitute y 2 into (3), x 3 2(2) 1 The solution of the simultaneous equations is x 1, y (1) (2) Method of Substitution
2009 Chung Tai Educational Press. All rights reserved. © Method of Elimination (1) – (2),5y 10 y 2y 2 Substitute y 2 into (1), x 2(2) 3 x 1 The solution of the simultaneous equations is x 1, y (1) (2)
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