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In the following questions two equation ...

In the following questions two equation numbered I and II are given You have to solve both equations and . . . . .
(i) `5x^(2)-18x+9=0`
(ii) `20y^(2)-13y+2=0`

A

`xlty`

B

x=y

C

`xgty`

D

none of these

Text Solution

AI Generated Solution

The correct Answer is:
To solve the given equations step by step, we will start with the first equation and then proceed to the second one. ### Step 1: Solve the first equation \(5x^2 - 18x + 9 = 0\) 1. **Identify coefficients**: Here, \(a = 5\), \(b = -18\), and \(c = 9\). 2. **Calculate the product \(ac\)**: \[ ac = 5 \times 9 = 45 \] 3. **Find two numbers that multiply to \(ac\) (45) and add to \(b\) (-18)**: The numbers are \(-15\) and \(-3\) because: \[ -15 \times -3 = 45 \quad \text{and} \quad -15 + (-3) = -18 \] 4. **Rewrite the equation**: \[ 5x^2 - 15x - 3x + 9 = 0 \] 5. **Factor by grouping**: \[ (5x^2 - 15x) + (-3x + 9) = 0 \] Factor out common terms: \[ 5x(x - 3) - 3(x - 3) = 0 \] This gives: \[ (5x - 3)(x - 3) = 0 \] 6. **Set each factor to zero**: \[ 5x - 3 = 0 \quad \text{or} \quad x - 3 = 0 \] 7. **Solve for \(x\)**: \[ x = \frac{3}{5} \quad \text{or} \quad x = 3 \] ### Step 2: Solve the second equation \(20y^2 - 13y + 2 = 0\) 1. **Identify coefficients**: Here, \(a = 20\), \(b = -13\), and \(c = 2\). 2. **Calculate the product \(ac\)**: \[ ac = 20 \times 2 = 40 \] 3. **Find two numbers that multiply to \(ac\) (40) and add to \(b\) (-13)**: The numbers are \(-8\) and \(-5\) because: \[ -8 \times -5 = 40 \quad \text{and} \quad -8 + (-5) = -13 \] 4. **Rewrite the equation**: \[ 20y^2 - 8y - 5y + 2 = 0 \] 5. **Factor by grouping**: \[ (20y^2 - 8y) + (-5y + 2) = 0 \] Factor out common terms: \[ 4y(5y - 2) - 1(5y - 2) = 0 \] This gives: \[ (5y - 2)(4y - 1) = 0 \] 6. **Set each factor to zero**: \[ 5y - 2 = 0 \quad \text{or} \quad 4y - 1 = 0 \] 7. **Solve for \(y\)**: \[ y = \frac{2}{5} \quad \text{or} \quad y = \frac{1}{4} \] ### Final Solutions: - For the first equation, the solutions are \(x = 3\) and \(x = \frac{3}{5}\). - For the second equation, the solutions are \(y = \frac{2}{5}\) and \(y = \frac{1}{4}\). ---
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