Question

please help me answer these 2 questions ​

Answer 1

Step-by-step explanation:

For 22.(a)

• By splitting the middle term
• Observe that before a^2 there is 2 also
• Then multiply 4 and 2
• Resulting we get 8 and then using 8 as the splitting value
• We get answer 2a+1 and a-1 as factors

Answer 2

Answer:

21. (a) (y + 1)(8y - 15)

     (b) (y + 1)(x³ + 8y - 15)

22. (a) (a - 4)(2a + 1)

      (b) (a - 4)(2a - 5b + 1)

Step-by-step explanation:

Given Questions :

21. (a) 8y² - 7y - 15

     (b) x³y + x³ + 8y² - 7y - 15

22. (a) 2a² - 7a - 4

      (b) 2a² - 7a - 4 - 5ab + 20b

To find :

Factorize the given expressions

Solution :

21. (a)

8y² - 7y - 15

⇒ 8y² + 8y - 15y - 15

⇒ 8y(y + 1) - 15(y + 1)

⇒ (y + 1)(8y - 15)

_____________________

21. (b)

x³y + x³ + 8y² - 7y - 15

⇒ x³(y+1) + 8y² - 7y - 15

From 21. (a),

⇒ x³(y+1) + (y + 1)(8y - 15)

⇒ (y + 1)(x³ + 8y - 15)

______________________

22.(a)

2a² - 7a - 4

⇒ 2a² - 8a + a - 4

⇒ 2a(a - 4) + 1(a-4)

⇒ (a - 4)(2a + 1)

___________________

22. (b)

2a² - 7a - 4 - 5ab + 20b

From 22. (a),

⇒ (a - 4)(2a + 1) -5b(a - 4)

⇒ (a - 4)(2a + 1 - 5b)

⇒ (a - 4)(2a - 5b + 1)

Hope it helps!!