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quick completing the square question

If we have 3x^2+4x+1 in the form a(x+b)+c would this be correct? 3(x+2/3)^2 +7/3
Original post by hazbaz
If we have 3x^2+4x+1 in the form a(x+b)+c would this be correct? 3(x+2/3)^2 +7/3


a and b, yes. c no.
Reply 2
Avatar for plmqaz
plmqaz
isn't it -1/9 instead of 7/3.
Reply 3
Avatar for plmqaz
plmqaz
for c i think it's 1/3 - (2/3)^2.
Original post by plmqaz
for c i think it's 1/3 - (2/3)^2.


Almost, you also took out a factor of 3 originally from the equation which you haven't brought back in.
Reply 5
Avatar for hazbaz
hazbaz
OP
11
had a feeling c wasnt correct dont i dived the 1 by 3 to start of with to get 1/3 then when i square the 2/3 i get 4/9 + that to 1/3= 7/9 to get to 1 i need to add 2/9...
c = -1/3 as already mentioned
Reply 7
Avatar for adie_raz
adie_raz
1
ok 3(2/3)^2 = 4/3, you want 4/3 +c = 1 so 1-4/3=c so c = -1/3
Reply 8
Avatar for hazbaz
hazbaz
OP
11
yep workd it out dunno waht i was doing before lol

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