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# Solve for (x+y)^3

Please show me work of how to solve this problem. I've been beating myself up! Thanks.

### 3 Answers by Expert Tutors

Kristin R. | NJ Certified Teacher - Top Rated Tutor - Intro thru AP Chemistry!NJ Certified Teacher - Top Rated Tutor -...
4.9 4.9 (144 lesson ratings) (144)
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(x+y)² =(x+y)(x+y)    Then you FOIL (First, outer, inner, last)

(x+y)² =(x+y)(x+y) = xx + xy + xy + yy [and when you combine like terms] = x² + 2xy + y²

(x+y)3 = (x² + 2xy + y²)(x+y) Then you FOIL (First, outer, inner, last)

(x+y)3 = (x² + 2xy + y²)(x+y) = x2x +2xxy + xy2 + x2y + 2xyy + y2y [and when you combine like terms] = x3 + 3x2y+ 3xy2 + y3

Thank you, Kristin! How did you make exponents on the computer? I couldn't figure that out.

Use Microsoft Word and hold the control, shift, and equals key for superscript. Hold   the control and equal key only for subscript.

If that's the case, shouldn't you get the original expression- (x+3)^3- as your answer after you factored your answer -x3 + 3x2y+ 3xy2 + y3?
Paul T. | Mathematics, Spanish, Writing and World History TutorMathematics, Spanish, Writing and World ...
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To make the exponents, use the shortcut for superscripts: Press CTRL+SHIFT+=; then release the 3 keys and type whatever exponent you wish to insert.