Question

use direct method to evaluate the following products (b-3) (b-5)​

Answer 1

Step-by-step explanation:

(i) (x + 8) (x + 3) = (x × x) + (x × 3) + (8 × x) + (8 × 3)

= x2 + 3x + 8x + 24

= x2 + 11x + 24

(ii) (y + 5) (y – 3) = (y × y) + (y × (-3)) + (5 × y) + (5 × (-3))

= y2 + (-3y) + (5y) – 15

= y2 – 3y + 5y – 15

= y2 + 2y – 15

(iii) (a- 8) (a + 2) = (a × a) + (a × 2) + (-8) × a + (-8) (2)

= a2 + 2a – 8a – 16

= a2 – 6a – 16

(iv) (b – 3) (b – 5) = (b × b) + (b × (-5) + (-3) × b + (-3) (-5)

= b2 – 5b – 3b + 15

= b2 – 8b + 15

(v) (3x -2y) (2x + y) = (3x × 2x) + (3x × y) + (-2y × 2x) + (-2y × y)

= 6x2 + 3xy – 4xy – 2y2

= 6x2 – xy – 2y2

(vi) (5a + 16) (3a – 7) = (5a × 3a) + (5a × (-7) + (16 × 3a) + 16 × (-7)

= 15a2 + (-35a) + 48a + (-112)

= 15a2 – 35a + 48a – 112

= 15a2 + 13a – 112

(vii) (8 – b) (3 + b) = (8 × 3) + (8 × b) + (-b × 3) + (-b × b)

= 24 + 8b – 3b – b2

= 24 + 5b – b2

Answer 2

Answer:

hers your answer........ b2-8b+15.............