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Given possible expression for the length...

Given possible expression for the length and breadth of each of the following rectangles if.
(i) Area `=(x^(2)+5sqrt5x+30)` sq.unit.
(ii) Area `=(24 x^(2)-26x-8)` sq. unit

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To solve the given problem, we need to find the possible expressions for the length and breadth of rectangles based on the provided areas. Let's tackle each part step by step. ### Part (i): Area = \(x^2 + 5\sqrt{5}x + 30\) sq. units 1. **Identify the area expression**: The area of the rectangle is given as \(A = x^2 + 5\sqrt{5}x + 30\). 2. **Factor the quadratic expression**: We need to factor this expression into two binomials. We will use the middle-term splitting method. - The expression can be represented in the form \(ax^2 + bx + c\) where: - \(a = 1\) - \(b = 5\sqrt{5}\) - \(c = 30\) 3. **Find two numbers that multiply to \(ac\) and add to \(b\)**: - Here, \(ac = 1 \times 30 = 30\). - We need two numbers that multiply to \(30\) and add to \(5\sqrt{5}\). - The numbers \(3\sqrt{5}\) and \(2\sqrt{5}\) satisfy this condition since: - \(3\sqrt{5} + 2\sqrt{5} = 5\sqrt{5}\) - \(3\sqrt{5} \times 2\sqrt{5} = 6 \times 5 = 30\) 4. **Rewrite the expression**: - Rewrite the quadratic as: \[ x^2 + 3\sqrt{5}x + 2\sqrt{5}x + 30 \] 5. **Group the terms**: - Group the first two and the last two terms: \[ (x^2 + 3\sqrt{5}x) + (2\sqrt{5}x + 30) \] 6. **Factor by grouping**: - Factor out the common terms: \[ x(x + 3\sqrt{5}) + 2\sqrt{5}(x + 3\sqrt{5}) \] - This gives: \[ (x + 3\sqrt{5})(x + 2\sqrt{5}) \] 7. **Identify length and breadth**: - Therefore, the possible expressions for the length and breadth are: \[ \text{Length} = (x + 3\sqrt{5}), \quad \text{Breadth} = (x + 2\sqrt{5}) \] ### Part (ii): Area = \(24x^2 - 26x - 8\) sq. units 1. **Identify the area expression**: The area of the rectangle is given as \(A = 24x^2 - 26x - 8\). 2. **Factor out the common factor**: - Notice that all terms are divisible by \(2\): \[ 2(12x^2 - 13x - 4) \] 3. **Factor the quadratic expression**: - Now we need to factor \(12x^2 - 13x - 4\). - Here, \(a = 12\), \(b = -13\), and \(c = -4\). - We need two numbers that multiply to \(ac = 12 \times -4 = -48\) and add to \(-13\). - The numbers \(-16\) and \(3\) satisfy this condition since: - \(-16 + 3 = -13\) - \(-16 \times 3 = -48\) 4. **Rewrite the expression**: - Rewrite the quadratic as: \[ 12x^2 - 16x + 3x - 4 \] 5. **Group the terms**: - Group the first two and the last two terms: \[ (12x^2 - 16x) + (3x - 4) \] 6. **Factor by grouping**: - Factor out the common terms: \[ 4x(3x - 4) + 1(3x - 4) \] - This gives: \[ (3x - 4)(4x + 1) \] 7. **Identify length and breadth**: - Therefore, the possible expressions for the length and breadth are: \[ \text{Length} = (3x - 4), \quad \text{Breadth} = (4x + 1) \] ### Summary of Solutions: - For Part (i): Length = \(x + 3\sqrt{5}\), Breadth = \(x + 2\sqrt{5}\) - For Part (ii): Length = \(3x - 4\), Breadth = \(4x + 1\)
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CBSE COMPLEMENTARY MATERIAL-POLYNOMIALS-Part C
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