Trying to find the right answer to this..

(3x - 5y - 4) (9x 2 + 25y 2 + 15xy + 12x - 20y + 16) = {(3x) + (-5y) + (-4)} {(3x) 2 + (-5y) 2 + (-4) 2 - (3x) (-5y) - (-5y) (-4) - (-4) (3x)} = (3x) 3 + (-5y) 3 + (-4) 3 - 3 (3x) (-5y) (-4) = 27x 3 - 125y 3 - 64 - 180cy.

Previous Year Papers

Download Solved Question Papers Free for Offline Practice and view Solutions Online.

Test Series

Take Zigya Full and Sectional Test Series. Time it out for real assessment and get your results instantly.

Test Yourself

Practice and master your preparation for a specific topic or chapter. Check you scores at the end of the test.

Polynomials

Short Answer Type

161.

Simplify: (x + y)³ - (x - y)³ - 6y(x²- y²)

795 Views

162. If x² + px + q = (x + a)(x + b), then factorise x² + pxy + qy².

326 Views

163. Prove that: (a + b)³ + (b + c)³ + (c + a)³ - 3(a + b)(b + c)(c + a) = 2(a³ + b³+ c³ - 3abc).

128 Views

164. Evaluate using suitable identify: (999)³.

344 Views

165. Multiply 9x² + 25y² + 15xy + 12x -20y + 16 by 3x - 5y - 4 using suitable identity.

(3x - 5y - 4) (9x² + 25y² + 15xy + 12x - 20y + 16)
= {(3x) + (-5y) + (-4)} {(3x)² + (-5y)² + (-4)² - (3x) (-5y) - (-5y) (-4) - (-4) (3x)}
= (3x)³ + (-5y)³ + (-4)³ - 3 (3x) (-5y) (-4)
= 27x³ - 125y³ - 64 - 180cy.