solve by extracting the square roots. list both the exact solution and hte decimal solution.
thank you
2007-08-26 09:07:44 · 6 answers · asked by Li 1 in Science & Mathematics ➔ Mathematics
(x - 5) = ± √20
(x - 5) = ± 2√5
x = 5 ± 2√5
x = 9.472 , x = 0.528
2007-08-26 09:48:19 · answer #1 · answered by Como 7 · 2⤊ 0⤋
(x-5)^2 = 20
=> x-5 = +/- â20
=> x = 5 +/- â20
=> x = 5 +/- â(4*5)
=> x = 5 +/- 2â5
=> x = 5 + 2â5 OR => x = 5 - 2â5 .......exact solution
AND
=> x = 9.472 OR x = 0.528 ....decimal solution.
2007-08-26 09:19:07 · answer #2 · answered by harry m 6 · 0⤊ 1⤋
square root both side ;
x-5 = sqr (20)
x-5 = 4.4721
add 5 to both sides
x-5+5 = 4.4721 +5
x = 9.4721 ( decimal solution)
x = 9.47 (exact solution)
2007-08-26 09:27:50 · answer #3 · answered by wuyex 1 · 0⤊ 1⤋
(x - 5)² = 20
x - 5 = â20
x - 5 = 2â5
x = 2â5 + 5
x â 9.4721359549995793928183473374626
2007-08-26 09:19:09 · answer #4 · answered by The Glorious S.O.B. 7 · 1⤊ 1⤋
(x-5)^2=20
or x^2-10x+25=20
or x^2-10x+5=0
or x={-(-10)+-sq rt(10^2-4.1.5)}/2.1
or x={10+-sq rt(100-20)}/2
or x={10+-sq rt(80)}/2
or x=5+-sq rt(4^2.5)/2
or x=5+-4sq rt(5)/2
or x=5+-2sq rt(5) ans
2007-08-26 09:23:27 · answer #5 · answered by MAHAANIM07 4 · 1⤊ 1⤋
(x-5)^2=20
2x-5*2=20
2x-10=20
2x=20+10
2x=30
x=30:2
x=15
2007-08-26 09:52:20 · answer #6 · answered by little.dot 1 · 0⤊ 2⤋