Simplify
(i) - pqr (p² + q² + r²)
(ii) (px + qy) (ax - by)

Solution:

Let us use the distributive property in solving the problems.

(i) - pqr (p² + q² + r²) = - (pqr) × p² - (pqr) × q² - (pqr) × r² = - p³qr - pq³r - pqr³

(ii) (px + qy) (ax - by) = px (ax - by) + qy (ax - by) = apx² - pbxy + aqxy - qby²

✦ Try This: Simplify: xyz (x²yz - xy²z - xyz²)

xyz (x²yz - xy²z - xyz²) = (xyz) (x²yz) - (xyz)(xy²z)- (xyz)(xyz²)

= x³y²z² - x²y³z² - x²y²z³

☛ Also Check: NCERT Solutions for Class 8 Maths Chapter 9

NCERT Exemplar Class 8 Maths Chapter 7 Sample Problem 10

Simplify (i) - pqr (p² + q² + r²), (ii) (px + qy) (ax - by)

Summary:

Simplifying (i) - pqr (p² + q² + r²) (ii) (px + qy) (ax - by) we get - p³qr - pq³r - pqr³ and axp² - apx² - pbxy + aqxy - qby² respectively

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