How do you evaluate #(2x ^ { 9} - 3x ^ { 8} + 7x ^ { 7} + 7) - ( 4x ^ { 9} - 7x ^ { 8} + 4x ^ {7 } - 2)#?

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Answer 1 · 2017-11-22T23:49:37

See a solution process below:

First, remove all of the terms from parenthesis. Be careful to handle the signs of each individual term correctly:

#2x^9 - 3x^8 + 7x^7 + 7 - 4x^9 + 7x^8 - 4x^7 + 2#

Next, group like terms:

#2x^9 - 4x^9 - 3x^8 + 7x^8 + 7x^7 - 4x^7 + 7 + 2#

Now, combine like terms:

#(2 - 4)x^9 + (-3 + 7)x^8 + (7 - 4)x^7 + (7 + 2)#

#-2x^9 + 4x^8 + 3x^7 + 9#