How do you foil #(2x+5)(4x-3)#?

1 Answer
Alan P.
Aug 8, 2015

#8x^2+14x-15#

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: #(2x+5)(4x-3)#
#color(white)("XXXX")#First terms: #2x, 4x##color(white)("XXXX")#Product #= 8x^2#
#color(white)("XXXX")#Outside terms: #2x, -3##color(white)("XXXX")#Product #= -6x#
#color(white)("XXXX")#Inside terms: #5, 4x##color(white)("XXXX")#Product #= 20x#
#color(white)("XXXX")#Last terms: 5, -3##color(white)("XXXX")#Product #= -15#

Sum
#color(white)("XXXX")##= 8x^2-6x+20x-15#

#color(white)("XXXX")##= 8x^2+14x-15#

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