complete the square
2b^2-b-7=14
thanks
2007-06-04 17:01:10 · 6 answers · asked by ღßutterflyღ 3 in Science & Mathematics ➔ Mathematics
it is not a perfect square right
2007-06-04 17:06:15 · update #1
2.(b² - b/2 - 7/2) = 14
b² - b/2 - 7/2 = 7
(b² - b/2 + 1/16) - 56/16 = 112/16 + 1/16
(b - 1/4)² = 169/16
b - 1/4 = ± 13/4
b = 1/4 ± 13/4
b = 14/4 , - 12/4
b = 7/2 , b = - 3
2007-06-04 22:25:21 · answer #1 · answered by Como 7 · 0⤊ 0⤋
2b^2-b-7=14
2b^2-b+1/8 -7-1/8=14
(bâ2-â2 /4)^2-7 1/8=14
(bâ2-â2 /4)^2=21â
bâ2-â2 /4=±â21.125
b-4=±(â2 /2)â21.125
b-4=±(1/2) â42.25
b-4=±(1/2)6.5=3.25
b=4±3.25
b=0.75
b=7.25
2007-06-05 00:14:12 · answer #2 · answered by yupchagee 7 · 0⤊ 1⤋
bring all to one side
2b^2 - b - 21 = 0
(2b -7)(b + 3) = 0
2b - 7 = 0 , b + 3 = 0
b = 3.5 , b = -3
2007-06-05 00:05:24 · answer #3 · answered by mcbrocks 3 · 0⤊ 0⤋
2b^2-b = 21
b(2b-1) = 21
thus, 21/b =2b-1
WHO CARES!!!!!
hahahahahahaha
sorry, very lazy, gotta go
2007-06-05 00:09:32 · answer #4 · answered by Anonymous · 0⤊ 0⤋
2b^2-b=21
b^2-(1/2)b=10.5
b^2-(1/2)b+(1/4)^2=10.5+(1/4)^2
(b-1/4)(b-1/4)=10.5625
b=10.8125
2007-06-05 00:48:16 · answer #5 · answered by Trevor W 1 · 0⤊ 1⤋
yeah sure!
Your answer is a multiple of two!
I really really hope this helps! just break it down!
Your welcome :)
2007-06-05 02:49:36 · answer #6 · answered by meohyeah 1 · 0⤊ 0⤋