Evaluate : (7x + 15y) (5x − 4y) - Mathematics

Evaluate : (7x + 15y) (5x − 4y)

Sum

(7x + 15y) (5x − 4y)

= 7x (5x − 4y) + 15y (5x − 4y)

= 35x² − 28xy + 75xy − 60y²

= 35x² + 47xy − 60y²

shaalaa.com

Product of Sum and Difference of Two Terms

Is there an error in this question or solution?

Chapter 12: Identities - Exercise 12 (A) [Page 150]

Chapter 12 Identities
Exercise 12 (A) | Q 5.08 | Page 150

Use the product (a + b) (a – b) = a² – b² to evaluate:
21 x 19

Use the product (a + b) (a – b) = a² – b² to evaluate:
9.8 x 10.2

Use the product (a + b) (a – b) = a² – b² to evaluate:
7.7 x 8.3

Use the product (a + b) (a – b) = a² – b² to evaluate:
4.6 x 5.4

Evaluate : `("a"/(2"b")+(2"b")/"a")("a"/(2"b")-(2"b")/"a")`

Evaluate : `(3"x"-1/(2"y"))(3"x"+1/(2"y"))`

Evaluate: (2a + 3) (2a − 3) (4a² + 9)

Evaluate: (a² + 5) (a² − 3)

Evaluate: (m + 3) (m − 3) (m² + 9)

Evaluate: (a + bc) (a − bc) (a² + b²c²)