quadratic formula question

ginny1029

Junior Member
Joined
Apr 25, 2009
Messages
53
im looking at my notes, trying to do this problem and im down to

x = -4 plus or minus the sq rt of 44 all over 2

x = -4 plus or minus the sq rt of 4 times 11 all over 2

x = -4 plus or minus 2 square root 11 all over 2

then the next step states

x = 2 (-2 plus or minus the square root of 11) all over 2

i dont get how that happened

can someone explain this please?
 
What can you factor out of 4 and 2sqrt[11]? :wink:
 
i could see the -4 and the 2 but thats not it

im sorry i dont get it from the -4 plus/minus 2 sq rt 11

to the

2(-2 plus/minus sq rt11)
 
ginny1029 said:
i could see the -4 and the 2 but thats not it

im sorry i dont get it from the -4 plus/minus 2 sq rt 11

to the

2(-2 plus/minus sq rt11)

Ok....
-4 +/- 2 sqrt(11)

2*(-2) +/- 2 * sqrt(11)

Do you see a common factor of 2? Remove that common factor:

2*(-2 +/- sqrt(11)]
 
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