Multiply using the FOIL method.
-$( x + 10 y ) ( x + 9 y )$
A) $x ^ { 2 } + 19 x y + 19 y ^ { 2 }$
B) $x + 19 x y + 90 y$
C) $x ^ { 2 } + 16 x y + 90 y ^ { 2 }$
D) $x ^ { 2 } + 19 x y + 90 y ^ { 2 }$

Question

Quizplus · Accepted Answer

Using the FOIL method (First, Outer, Inner, Last) to multiply $(x + 10y)(x + 9y)$, we get: First: $x \cdot x = x^2$, Outer: $x \cdot 9y = 9xy$, Inner: $10y \cdot x = 10xy$, Last: $10y \cdot 9y = 90y^2$. Adding these together gives $x^2 + 19xy + 90y^2$.

Multiply Using the FOIL Method (x+10y)(x+9y)( x + 10 y ) ( x + 9 y )(x+10y)(x+9y)

Multiply Using the FOIL Method $( x + 10 y ) ( x + 9 y )$