Question

13. Square of 9x - 7 xy is​

Answer 1

Answer:

$81x^2-126x^2y+29x^2y^2$

Step-by-step explanation:

Identity

$(x+y)^2=x^2+2xy+y^2$

∴$(9x-7xy)^2=81x^2-126x^2y+29x^2y^2$

Answer 2

Answer:

81 81x squared - 49x squared y squared - 126 81x squared - 49x squared y squared