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In each of the following find the value ...

In each of the following find the value of 'a'
`9x^(2) + (7a-5)x + 25 = (3x + 5)^(2)`

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To solve the equation \( 9x^{2} + (7a-5)x + 25 = (3x + 5)^{2} \) and find the value of \( a \), we can follow these steps: ### Step 1: Expand the right-hand side We start by expanding the right-hand side of the equation using the formula for the square of a binomial: \[ (a + b)^{2} = a^{2} + 2ab + b^{2} \] Here, \( a = 3x \) and \( b = 5 \). Therefore: \[ (3x + 5)^{2} = (3x)^{2} + 2(3x)(5) + (5)^{2} \] Calculating this gives: \[ (3x + 5)^{2} = 9x^{2} + 30x + 25 \] ### Step 2: Set the left-hand side equal to the expanded right-hand side Now we can rewrite the equation: \[ 9x^{2} + (7a - 5)x + 25 = 9x^{2} + 30x + 25 \] ### Step 3: Cancel out the common terms Next, we can cancel \( 9x^{2} \) and \( 25 \) from both sides: \[ (7a - 5)x = 30x \] ### Step 4: Equate the coefficients of \( x \) Since the coefficients of \( x \) must be equal, we can set: \[ 7a - 5 = 30 \] ### Step 5: Solve for \( a \) Now, we solve for \( a \): \[ 7a = 30 + 5 \] \[ 7a = 35 \] \[ a = \frac{35}{7} \] \[ a = 5 \] ### Final Answer Thus, the value of \( a \) is \( 5 \). ---
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ICSE-EXPANSIONS-Exercise 4(D)
  1. In the expansion of (2x^(2)-8) (x-4)^(2), find the value of coeffici...

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  2. In the expansion of (2x^(2)-8) (x-4)^(2), find the value of constant...

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  3. If x gt 0 and x^(2) +(1)/(9x^(2))= (25)/(36), find x^(3) + (1)/(27x^(3...

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  4. If 2(x^(2) + 1)= 5x, find x- (1)/(x)

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  5. If 2(x^(2) + 1)= 5x, find x^(3)- (1)/(x^(3))

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  6. If a^(2) + b^(2)= 34 and ab= 12, find: 3(a +b)^(2) + 5(a-b)^(2)

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  7. If a^(2) + b^(2)= 34 and ab= 12, find: 7(a-b)^(2) - 2(a +b)^(2)

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  8. If 3x- (4)/(x)= 4 and x ne 0, find 27 x^(3)- (64)/(x^(3))

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  9. If x^(2) + (1)/(x^(2))= 7 and x ne 0, find the value of : 7x^(3) + 8x-...

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  10. If x= (1)/(x) - 5 and x ne 5, find x^(2)- (1)/(x^(2))

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  11. If x= (1)/(5-x) and x ne 5, find x^(3) + (1)/(x^(3))

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  12. If 3a + 5b + 4c= 0, show that: 27a^(3) + 125b^(3) + 64 c^(3) = 180 abc

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  13. The sum of two numbers is 7 and the sum of their cubes is 133. Find th...

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  14. In each of the following find the value of 'a' 4x^(2) + ax + 9 = (2...

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  15. In each of the following find the value of 'a' 4x^(2) + ax + 9 = (2x...

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  16. In each of the following find the value of 'a' 9x^(2) + (7a-5)x + 25...

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  17. If (x^(2) + 1)/(x)= 3(1)/(3) and x gt 1, find x- (1)/(x)

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  18. If (x^(2) + 1)/(x)= 3(1)/(3) and x gt 1, find x^(3)- (1)/(x^(3))

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  19. The difference between two positive numbers is 4 and the difference be...

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  20. The difference between two positive numbers is 4 and the difference be...

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