expand (2x-5y)squared

Question

a. 4xsquared-20xy+25ysquared

b. 4xsquared+25ysquared

c. 4xsquared-20xy-25ysquared

d. 4xsquared-25ysquared

Answer 1

expanding a polynomial (2x-5y)² = (2x-5y)(2x-5y) 

= 2x*2x +2x*(-5y) +(-5y)*2x + (-5y)*(-5y)

= 4x² -10xy - 10xy + 25y²

= 4x² - 20xy + 25y²

Which is ANSWER A