Question

find the value of P cube minus Q cube if P minus Q equal to minus 7 and PQ equal to minus 10
class 9 maths polynomials ncert cbse​
will mark as brainlest for th 1st comnt sure

Answer 1

Answer:

-133

Step-by-step explanation:

first, we will find p^2 + q^2 from given information then substituting that value in a^3 - b^3 formula.

we will get -133 as answer.

p - q = -7

pq = -10

(p - q) ^2 = p^2 + q^2 - 2pq

(-7)^2 = p^2 + q^2 - (-20)

49 = p^2 + q^2 + 20

p^2 + q^2 = 49 - 20

p^2 + q^2 = 29

Now,

p^3 - q^3 = (p - q) (p^2 + q^2 + pq)

= -7 ( 29+(-10))

= -7 (29-10)

= -7*19

p^3 - q^3 = -133