How do you simplify #(7y -x)^2#?

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Answer 1 · 2017-01-25T16:49:24

#49y^2 + x^2 - 14xy #

It is a binomial squared:

# (a + b)^2 = a^2 + b^2 + 2ab#

Answer 2 · 2017-01-25T17:01:27

See below.

This is a binomial so we can make use of the standard formula

#(color(red)"a"-color(blue)"b")^2# #=# #color(red)"a"^2# - #2color(red)"a"color(blue)"b"# + #color(blue)"b"^2#

For our purposes, #color(red)("a"=7y# and #color(blue)("b"=x# . Putting the values in the above given equation we obtain:

#(7y -x)^2# = #49y^2 -2*7y*x + x^2#

#=># #(7y -x)^2# = #49y^2 -14xy + x^2#

Answer 3 · 2017-01-25T17:19:39

#49y^2-14yx+x^2#

#(7y-x)^2#

#color(white)(aaaaaaaaaaaaa)##7y-x#

#color(white)(aaaaaaaaaaa)##---#

#color(white)(aaaaaaaaaaaaa)##49y^2-7yx#

#color(white)(aaaaaaaaaaaaaaaaa)##-7yx+x^2#

#color(white)(aaaaaaaaaaaaa)##------#

#color(white)(aaaaaaaaaaaa)##49y^2-14yx+x^2#