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(2sqrt(5) +3sqrt(7))^2 = (2sqrt(5) +3sqrt(7))(2sqrt(5) +3sqrt(7)) = 2sqrt(5)2sqrt(5) + 2sqrt(5)3sqrt(7) + 3sqrt(7)2sqrt(5) + 3sqrt(7)3sqrt(7) = 20 + 6sqrt(5)sqrt(7) + 6sqrt(7)sqrt(5) + 63 = 83 + 12sqrt(5)sqrt(7)
i don't undertsand is there a simlyer way to do it?
\[(a+b)^2=a^2+2ab+b^2\] use this here \[a=2\sqrt{5}\]\[b=3\sqrt{7}\]
not really. perhaps if i use the equation writer it will be clearer: \[(2\sqrt{5} +3\sqrt{7})^2 = (2\sqrt5 +3\sqrt7)(2\sqrt5+3\sqrt7)\] \[=2\sqrt5(2\sqrt5 + 3\sqrt7) + 3\sqrt7(2\sqrt5 + 3\sqrt7)\] \[= (2\sqrt5)(2\sqrt5) + (2\sqrt5)(3\sqrt7) + (3\sqrt7)(2\sqrt5) + (3\sqrt7)(3\sqrt7)\] \[=4(\sqrt5)^2 + (2\sqrt5)(3\sqrt7) + (2\sqrt5)(3\sqrt7)+ 9(\sqrt7)^2\]
ok ok thank u
I got something different. Tell me where i went wrong. Check the attached file(my solution).
\[\large (2\sqrt{5}+3\sqrt{7})^2 \neq (2\sqrt{5})^2+ (3\sqrt{7})^2\]
\[(a+b)^2= a^2+2ab+b^2\] Since:\[(a+b)^2=(a+b)(a+b)\]\[a(a+b)+b(a+b)\]\[a^2+ab+ba+b^2\]\[a^2+2ab+b^2\]
Thanks alot. I see my mistake now. I really appreciate your assistance.
you're Welcome :)
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