How do you foil # (y+7)(y+4)#?

1 Answer
Aug 8, 2015

Answer:

#(y+7)(y+4) = (y^2+11y+28)#

Explanation:

Evaluating the product of two binomials using FOIL:

Sum
#color(white)("XXXX")#product of First terms
#color(white)("XXXX")#product of Outside terms
#color(white)("XXXX")#product of Inside terms
#color(white)("XXXX")#product of Last terms

For the given example: #(y+7)(y+4)#
#color(white)("XXXX")#First terms: #y, y##color(white)("XXXX")#Product #= y^2#
#color(white)("XXXX")#Outside terms: #y, 4##color(white)("XXXX")#Product #= 4y#
#color(white)("XXXX")#Inside terms: #7, y##color(white)("XXXX")#Product #= 7y#
#color(white)("XXXX")#Last terms: 7, 4##color(white)("XXXX")#Product #= 28#

Sum
#color(white)("XXXX")##= y^2+4y+7y+28#

#color(white)("XXXX")##= y^2+11y+28#