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The algebraic sum of distances of the li...

The algebraic sum of distances of the line `ax + by + 2 = 0` from `(1,2), (2,1) and (3,5)` is zero and the lines `bx - ay + 4 = 0` and `3x + 4y + 5=0` cut the coordinate axes at concyclic points. Then (a) `a+b=-2/7` (b) area of triangle formed by the line `ax+by+2=0` with coordinate axes is `14/5` (c) line `ax+by+3=0` always passes through the point `(-1,1)` (d) max `{a,b}=5/7`

A

`a +b =- (2)/(7)`

B

area of the triangle formed by the line `ax +by +2 = 0` with coordinate axes is `(14)/(5)`

C

line `ax +by +3 = 0` always passes through the point `(-1,1)`

D

max `{a,b} = (5)/(7)`

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To solve the given problem step by step, we will analyze the conditions provided and derive the necessary equations. ### Step 1: Understand the Given Line and Points We have the line equation: \[ ax + by + 2 = 0 \] We need to find the algebraic sum of distances from the points \( (1, 2), (2, 1), (3, 5) \) to this line, and set it to zero. ### Step 2: Calculate the Distance from a Point to a Line The distance \( d \) from a point \( (x_0, y_0) \) to the line \( Ax + By + C = 0 \) is given by: \[ d = \frac{|Ax_0 + By_0 + C|}{\sqrt{A^2 + B^2}} \] For our line \( ax + by + 2 = 0 \), \( A = a, B = b, C = 2 \). ### Step 3: Calculate Distances for Each Point 1. For point \( (1, 2) \): \[ d_1 = \frac{|a(1) + b(2) + 2|}{\sqrt{a^2 + b^2}} = \frac{|a + 2b + 2|}{\sqrt{a^2 + b^2}} \] 2. For point \( (2, 1) \): \[ d_2 = \frac{|a(2) + b(1) + 2|}{\sqrt{a^2 + b^2}} = \frac{|2a + b + 2|}{\sqrt{a^2 + b^2}} \] 3. For point \( (3, 5) \): \[ d_3 = \frac{|a(3) + b(5) + 2|}{\sqrt{a^2 + b^2}} = \frac{|3a + 5b + 2|}{\sqrt{a^2 + b^2}} \] ### Step 4: Set Up the Equation The algebraic sum of these distances is given to be zero: \[ d_1 + d_2 + d_3 = 0 \] This implies: \[ |a + 2b + 2| + |2a + b + 2| + |3a + 5b + 2| = 0 \] Since distances cannot be negative, each term must equal zero: \[ a + 2b + 2 = 0 \quad (1) \] \[ 2a + b + 2 = 0 \quad (2) \] \[ 3a + 5b + 2 = 0 \quad (3) \] ### Step 5: Solve the System of Equations From equation (1): \[ a + 2b = -2 \quad \Rightarrow \quad a = -2 - 2b \quad (4) \] Substituting (4) into (2): \[ 2(-2 - 2b) + b + 2 = 0 \] \[ -4 - 4b + b + 2 = 0 \] \[ -3b - 2 = 0 \quad \Rightarrow \quad b = -\frac{2}{3} \] Now substituting \( b \) back into (4): \[ a = -2 - 2\left(-\frac{2}{3}\right) = -2 + \frac{4}{3} = -\frac{6}{3} + \frac{4}{3} = -\frac{2}{3} \] ### Step 6: Verify the Conditions Now we have \( a = -\frac{2}{3} \) and \( b = -\frac{2}{3} \). ### Step 7: Check Other Conditions 1. **Area of Triangle**: The area of the triangle formed by the line with the axes can be calculated using the formula: \[ \text{Area} = \frac{1}{2} \times \text{base} \times \text{height} \] The intercepts can be found by setting \( y = 0 \) and \( x = 0 \). 2. **Concyclic Points**: Check if the lines \( bx - ay + 4 = 0 \) and \( 3x + 4y + 5 = 0 \) cut the axes at concyclic points. 3. **Line Passing through Point**: Check if the line \( ax + by + 3 = 0 \) passes through \( (-1, 1) \). ### Conclusion After solving the equations and verifying the conditions, we can conclude which options are correct based on the derived values of \( a \) and \( b \).

To solve the given problem step by step, we will analyze the conditions provided and derive the necessary equations. ### Step 1: Understand the Given Line and Points We have the line equation: \[ ax + by + 2 = 0 \] We need to find the algebraic sum of distances from the points \( (1, 2), (2, 1), (3, 5) \) to this line, and set it to zero. ### Step 2: Calculate the Distance from a Point to a Line ...
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