Sunday 5 October 2014

SIMULTANEOUS EQUATIONS 2


Solve the following equations by substitution method.
x + y = 9
x + 3y = 13

Solution

x + y = 9 ----------- (i)
x + 3y = 13 ---------- (ii)

from equation (i)

x + y = 9
x = 9- y ----------(iii)

substitute equation (iii) in (ii) above,

x + 3y = 13

(9- y)  + 3y = 13

9+2y = 13

2y = 13 - 9

2y = 4
2      2

y = 2


From equation (iii)

x = 9- 2 ----------(iii)
x = 9- 2
 x = 7

Hence x=7 and y=2.

TRY THIS………………………..

4x - y = 20

3x + 2y = 70

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