Page 137 - Start Up Mathematics_8 (Non CCE)

3 6 7
Example 2: Solve the equation x - = and check the solution.
4 5 10

Solution: 3 x - 6 = 7 Check:
4 5 10
3 6 3 38 6
3 6 6 7 6 LHS = x - = ¥ -
fi x - + = + 4 5 4 15 5
4 5 5 10 5 338¥ 6

6 = 415¥ - 5
(Adding to both sides)
5 19 6
= -
3 712+ 19 10 5
fi x = =
4 10 10 = 19 -12
3 19 10
fi x =
4 10 = 7 = RHS
4 3 19 4 10
fi ¥ x = ¥
3 4 10 3 fi LHS = RHS
4
(Multiplying both sides by ) 38
3 So, x = is the solution of the given equation.
19 4¥ 19 2¥ 38 15
fi x = = =
10 3¥ 53¥ 15

38
\ x =
15

x - 2 x - 3
Example 3: Solve - =1 and check the solution.
4 5
Solution: LCM of 4 and 5 = 20
Check:
5(x - 2) - 4 (x - 3)
= 1
20 x - 2 x - 3
LHS = -
5x - 104x- + 12 4 5
fi = 1
20 18 2- 18 3- 16 15
= - = -
(5x - 4x ) (12 10+ - ) 4 5 4 5
fi = 1 = 4 – 3 = 1 = RHS
20
fi LHS = RHS
x + 2
fi =1 So, x = 18 is the solution of the given equation.
20
(x + 2 )
fi ¥ 20 = ¥1 20
20

(Multiplying both sides by 20)
fi x + 2 = 20

fi x + 2 – 2 = 20 – 2
(Subtracting 2 from both sides)
fi x = 18

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