Question

(2x² - 5y) (5x + 2y²); x = 2 y = - 1​

Answer 1

x = 2

y = -1

(2x² - 5y) (5x + 2y²)

= (2 × 2² - 5 × -1) (5 × 2 + 2 × -1²)

= (2 × 2² - 5 × -1) × (5 × 2 + 2 × -1²)

= (2 × 4 - 5 × -1) × (5 × 2 + 2 × -1)

= 8 - 5 × 10 + (-2)

= 3 × 10 - 2

= 30 - 2

= 28