Question 678585


a+b=1


(a+b)^2=1^2


a^2 + 2ab + b^2=1


(a^2 + b^2) + 2ab=1


(2) + 2ab=1


2ab=1-2


2ab=-1


(2ab)^2=(-1)^2


4a^2b^2=1


2a^2b^2=1/2


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a^2 +b^2 = 2


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


a^4 + 2a^2b^2+b^4 = 4


a^4 + 1/2 + b^4 = 4


a^4 + b^4 = 4 - 1/2


a^4 + b^4 = <font color="red">7/2</font>