How do u rearange
4x^3+5x+3=0
to give a value for x
2007-08-17 20:04:55 · 4 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
I can rearrange: 4x³ + 5x + 3 = 0 as:
4x³ + 2x² - 2x² - x + 6x + 3 = 0 and then write the same
= 2x²(2x + 1) - x(2x + 1) + 3(2x + 1) = 0 or
(2x + 1)(2x² - x + 3) = 0.
Since product of two expressions is zero, either (2x + 1) = 0
---> x = - ½.
Or 2x² - x + 3 = 0. Solving this quadratic: x = ¼[1 ± √(23)].
So finally either x = - ½ or x = ¼[1 ± √(23)] are the solutions of the given equation.
2007-08-17 21:00:21 · answer #1 · answered by quidwai 4 · 2⤊ 0⤋
4x^3+5x+3=0
(2x + 1)(2x^2 - x + 3) = 0
(Actually, I plotted the formula in excel)
2007-08-17 21:01:38 · answer #2 · answered by ancient_nerd 2 · 0⤊ 0⤋
f(x) = 4x³ + 5x + 3
f(-1/2) = - 1/2 - 5/2 + 3 = 0
This shows that x = (-1/2) is a factor of f(x)
To find other factors use synthetic division:-
(-1/2)|4****0****5****3
******|****-2****1***-3
******|4***-2****6***0
f(x) = (x + 1/2)(4x² - 2x + 6)
x + 1/2 = 0
x = - 1/2 is a factor
Other factors are from:-
4x² - 2x + 6 = 0
2x² - x + 3 = 0
x = [1 ± √(1 - 24)] / 2
x = [1 ± √( - 23) ] / 2
x = [1 ± i √(23)] / 2
2007-08-18 05:05:11 · answer #3 · answered by Como 7 · 0⤊ 0⤋
a million. take ln of the two facets to get ln174=ln535+(x/seventy 9)ln(0.fifty seven) 2. simplify ln174-ln535=(x/seventy 9)ln(0.fifty seven) ln(174/535)/ln(0.fifty seven)=x/seventy 9 x=79ln(174/535)/ln(0.fifty seven) 3. calculate to get x=278
2016-12-30 18:03:48 · answer #4 · answered by Anonymous · 0⤊ 0⤋