7.2 Simultaneous Equations
Two or more equations (system of equations) that are true at the same time and are therefore satisfied by the same values of unknowns involved; are called simultaneous equations.
The equations 2 x + y = 3
3x + 4y = 2
are simultaneous equations having solution x = 2, y = 1
Method of solving the simultaneous equations :
1. Method of substitution
This method involves substituting one equation into another.
Example Solve the equations x = 2 + y
x + 2 y = 17
Solution: x = 2 + y . . . (1)
x + 2 y = 17 . . . (2)
From (1), Substitute (y + 2) for x in (2)
( y + 2) + 2 y = 17
3 y + 2 = 17
Transposing, 3 y = 15
\ y = 5
Now insert y = 5 in (1)
x = 5 + 2
x = 7
\ x = 7 , y = 5 . . . Required solution
