Question

Solve the following equation by trial and error method :

(i) 3 X + 5 = 14

(ii) 2p – 7 = 5

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Answer 1

1). We have 3x + 5 = 14

Putting x=1 in LHS , we get

3 (1) + 5 = 3 + 5 = 8 ≠ RHS

Putting x = 2 in LHS , we get

3(2)+ 5 =6+5=11≠RHS

Putting x=3 in LHS , we get

3(3)+5 = 9+5=14 = RHS

Here ,x=3 is the solution of the equation 3x + 5 = 14

2).We have 2p-7 = 5

Putting p=1 in LHS ,we get

2(1)-7 = 2-7 = -5

Putting p = 2 in LHS ,we get

2(2)-7=4-7 = -3

Putting p=3 in LHS ,we get

2(3)-7 = 6 – 7 = -1

Putting p = 4 in LHS , we get

2(4) – 7 = 8 – 7 = 1

Putting p= 5 in LHS , we get

2(5) – 7 = 10-7 = 3

Putting p= 6 in LHS ,we get2(6) – 7 = 12 – 7 = 5

Here , p=6 is the solution of the equation 2p-7=5

Answer 2

(1) 3x+5=14
=3x+5-5=14-5
=3x=9
=x=9/3
=x=3

(2) 2p-7=5
=2p-7+7=5+7
=2p=12
=p=12/2
=p=6