Question

$<b><i>$Find the value of expression (81x² + 16y² - 72xy), when x = 2/3 and y = 3/4.

Answer 1

$<b><i>$Solution :—
......................................................

Given,

x = 2/3 and y = 3/4

•°• The expression of 81x² + 16y² - 72xy

= (9x)² + (4y)² - 2.9x.4y

= (9x - 4y)²

= (9 × 2/3 - 4 × 3/4)²

= (6 - 3)²

= 3²

= 3 × 3

= 9

Answer 2

Answer:9

Step-by-step explanation:put the values of x and y

$81{(2/3)}^{2}+16{(3/4)}^{2}-{36}×{2}/{3}×{3}/{4}$=$36-36+9$=$9$

Therefore, the answer is $9$