Solve the following equations by the trial and error method:

(i) [tex]5x - 3 = 12[/tex]

(ii) [tex]7y + 3 = -21[/tex]

(iii) [tex]2y - 5 = 17[/tex]

(iv) [tex]4z - 6 = 10[/tex]



Answer :

Let's solve the given equations step by step through the trial and error method:

### (i) \(5x - 3 = 12\)

1. Assume an initial value for \( x \) and substitute it into the equation to check if it satisfies the equation:
- Let's try \( x = 2 \):
[tex]\[ 5(2) - 3 = 10 - 3 = 7 \quad (\text{Not equal to 12}) \][/tex]
- Let's try \( x = 3 \):
[tex]\[ 5(3) - 3 = 15 - 3 = 12 \quad (\text{Equal to 12}) \][/tex]

So, \( x = 3 \) is the solution.

### (ii) \(7y + 3 = -21\)

1. Assume an initial value for \( y \) and substitute it into the equation to check if it satisfies the equation:
- Let's try \( y = -3 \):
[tex]\[ 7(-3) + 3 = -21 + 3 = -18 \quad (\text{Not equal to -21}) \][/tex]
- Let's try \( y = -4 \):
[tex]\[ 7(-4) + 3 = -28 + 3 = -25 \quad (\text{Not equal to -21}) \][/tex]
- Let's try \( y = -3.5 \):
[tex]\[ 7(-3.4285714285714284) + 3 = -24 + 3 = -21 \quad (\text{Equal to -21}) \][/tex]

So, \( y \approx -3.4285714285714284 \) is the solution.

### (iii) \(2y - 5 = 17\)

1. Assume an initial value for \( y \) and substitute it into the equation to check if it satisfies the equation:
- Let's try \( y = 10 \):
[tex]\[ 2(10) - 5 = 20 - 5 = 15 \quad (\text{Not equal to 17}) \][/tex]
- Let's try \( y = 11 \):
[tex]\[ 2(11) - 5 = 22 - 5 = 17 \quad (\text{Equal to 17}) \][/tex]

So, \( y = 11 \) is the solution.

### (iv) \(4z - 6 = 10\)

1. Assume an initial value for \( z \) and substitute it into the equation to check if it satisfies the equation:
- Let's try \( z = 3 \):
[tex]\[ 4(3) - 6 = 12 - 6 = 6 \quad (\text{Not equal to 10}) \][/tex]
- Let's try \( z = 4 \):
[tex]\[ 4(4) - 6 = 16 - 6 = 10 \quad (\text{Equal to 10}) \][/tex]

So, \( z = 4 \) is the solution.

In summary, the solutions are:
1. \( x = 3 \)
2. \( y \approx -3.4285714285714284 \)
3. \( y = 11 \)
4. [tex]\( z = 4 \)[/tex]

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