i know if expanded and simplified it comes too x^3-9x^2+27x+91=0
2007-05-03 07:52:14 · 9 answers · asked by danny s 1 in Science & Mathematics ➔ Mathematics
Don't expand if you don't have to.
√(3-x) = 8/(3-x)
3-x = 64/(3-x)²
(3-x)^3 = 64
3 - x = 4
x = -1
2007-05-03 07:57:46 · answer #1 · answered by Philo 7 · 0⤊ 1⤋
square root(3-x)= 8/(3-x)
3-x = [8/(3-x)]^2
3-x = 64/(3-x)^2
(3-x)^3 = 64
3-x = 4
3-4 = x
x = -1
2007-05-03 08:43:27 · answer #2 · answered by Kemmy 6 · 0⤊ 0⤋
SQRT(3-x)=8/(3-x)
(3-x)=64/((3-x)^2) (squaring)
(3-x)^3=64 (multiplying by (3-x)^2)
3-x = 4 (cube rooting)
x = -1
2007-05-03 07:59:47 · answer #3 · answered by joncummins1968 4 · 0⤊ 1⤋
first 3-x>0 so x<3
call 3-x=z
sqrt z =8/z so squaring z^3=64 and z=4
so3-x=4 and x=-1
2007-05-03 08:01:12 · answer #4 · answered by santmann2002 7 · 0⤊ 1⤋
x^2-x-56=0 here pq=56 & p+q= -1 where p& q are numbers (x-8) (x+7)=0 x-8=0 or x+7=0 x = 8 or x = -7
2016-05-19 22:00:16 · answer #5 · answered by ? 3 · 0⤊ 0⤋
√(3 - x) = 8 / (3 - x)
3 - x = 64 / (3 - x)²
(3 - x)³ = 64
(3 - x) = 4
x = - 1
2007-05-03 08:40:54 · answer #6 · answered by Como 7 · 0⤊ 0⤋
(3-x)^3=64 , 3-x=4 , x=-1
2007-05-03 08:04:46 · answer #7 · answered by Anonymous · 0⤊ 1⤋
denote 3-x=y
root y=8/y ....y cannot be zero ....then x cannot be 3
second power gives
y = 64/y^2
meaning y^3 = 64
y=4
3-x=y
3-x=4
x= - 1
2007-05-03 08:03:19 · answer #8 · answered by lil' 2 · 0⤊ 1⤋
x=-1 or x=minus 1
2007-05-03 08:03:35 · answer #9 · answered by Anonymous · 0⤊ 1⤋