2006-10-08 13:59:46 · 18 answers · asked by Pierre W 1 in Science & Mathematics ➔ Mathematics
not a very tidy one i'm afraid
3x sqrd +3x =5
>>>>> 3x sqrd +3x - 5 = 0
using the quadratic formula,we have
x = (-3 +/-sqr rt (3 sqrd - 4*3*(-5))/6
= (-3 +/-sqr rt (69))/6
= 0.8844373105 or -1.8844373105
by calculator
i hope that this helps
2006-10-09 07:24:00 · answer #1 · answered by Anonymous · 0⤊ 0⤋
There are some classic mistakes in the algebra in some of these answers. Some are correct.
3x^2 + 3x = 5
Rearrange to give the normal quadratic form ax^2 + bx + c:
3x^2 + 3x - 5 = 0 Hence a =3 b=3 c= -5
You cannot solve this by factorisation as there are no whole number roots. Hence you have to use the quadratic formula:
x = -b +or - the square root of (b^2 - 4ac) all divided by 2a, It is difficult to type the formula but I am sure you have it:
Substituting for a.b and c gives:
x = -3 +or - the square root of 69 all divided by 6
This gives x = 0.884 or x = -1.88 (3 sf)
2006-10-08 20:54:03 · answer #2 · answered by RATTY 7 · 0⤊ 0⤋
3X²+3X=5
3X(X+1)=5
3X=5 V X+1=5
X=5/3 V X=4
2006-10-08 14:13:37 · answer #3 · answered by james 2 · 0⤊ 1⤋
Equations which are of the form ax^2 +bx + c=0 are in the standard form of what is called a quadratic equation.
You can arrive at the solution set by factoring when the coefficients are nice round numbers, but at all times you can find the solution by using what is known as the quadratic formula.
that is:
x=[(-b)+or - the square root of (b^2 - 4ac)]/2a
So put the equation in the quadratic form and put in a,b,and c.
3x^2+ 3x -5=0
x^2+x-5/3=0
a=1 b=1 c=(-5/3)
x= (-1)+ or- square root of 1-(-20/3)/2
x=(-1)+or-squ rt of 23/3]/2
x=[(-1)+ or- 2.77]/2
x=-.885, -1.885
2006-10-08 15:12:19 · answer #4 · answered by True Blue 6 · 0⤊ 0⤋
3xsquared + 3x isnt 5. combine like terms:3x + 3x = 6.now do exponents: 6sqaured = 6*6 = 36.thats your answer.
2006-10-12 12:48:07 · answer #5 · answered by bluemicky23 1 · 0⤊ 0⤋
3x^2 + 3x = 5
3x(x + 1) = 5
3x = 5 or x+1 = 5
x = 5/3 or x = 4
2006-10-08 14:06:18 · answer #6 · answered by aazib_1 3 · 1⤊ 2⤋
3xsquared +3x= 5 =
3xsquared +3x - 5= 0 since the quadratic formula equals 0 you can no use the quadratic equation-
- b +/- sqrt(b^2 - 4ac)
x = -----------------------
2a
- (3) +/- sqrt(3^2 - 4(3)(-5))
x = -----------------------
2(3)
- 3 +/- sqrt(69)
x = -----------------------= -1/2 +/- sqrt(69)
6
2006-10-08 14:22:42 · answer #7 · answered by luna y 1 · 0⤊ 1⤋
3x^2 + 3x = 5
3x^2 + 3x - 5 = 0
Use quadratic formula to solve
2006-10-08 14:19:31 · answer #8 · answered by Simon Says Touch Your Nose 5 · 0⤊ 1⤋
3x^2+3x-5=0
solve for x using the quadratic formula x = [âb ± â(b2 â 4ac)]/2a
2006-10-08 14:24:56 · answer #9 · answered by Anonymous · 0⤊ 1⤋
9+3x=5-9
3x=-4
take 4 divided by
x=-1.33333
2006-10-08 14:43:31 · answer #10 · answered by Anonymous · 0⤊ 0⤋