I have 2 problems I don't understand in solve using quadratic formula?

Question

first problem: x^2 - 2x = 15x - 10

second problem: x^2 - 3x -3 = 5

I have to show all work for these problems. Can someone please help?

Answer 1

first problem: x^2 - 2x = 15x - 10
x^2 - 2x = 15x - 10
x^2 - 17x = -10
x^2 - 17x + 10 = 0
x = [-(-17) +- sqrt((-17)^2 - 4*1*(10))]/(2*1)
x = [(17) +- sqrt(289 - 40)]/2
x = [17 +- sqrt(249)]/2


second problem: x^2 - 3x -3 = 5
x^2 - 3x - 3 = 5
x^2 - 3x - 8 = 0
x = [-(-3) +- sqrt((-3)^2 - 4*1*(-8))]/(2*1)
x = [(3) +- sqrt(9 + 32)]/2
x = [3 +- sqrt(41)]/2


I'll leave it for you to simplify/approximate the roots.

Answer 2

first you have to bring everything to one side. so the first equation will be: x^2 - 17x + 10 = 0. (by subtracting 15x and adding 10 to both sides.) then, a=1, b= (-17) and c=10. then you have to substitute that into the quadratic formula.
x=[-b +/- sqrt(b^2-4*a*c)] / (2a)

the second equation, by subtracting 5 from both sides, will be:
x^2 - 3x - 8 = 0
then do the same thing - substituting it into the QF.

ps - x^2 is the same as 1x^2, so a=1

Answer 3

are you trying to find x?

well..you do the work.. and i'll tell you how...okay..
first problem:
1. combine like terms from both sides. (-2x and 15x) < like you minus 15x from both sides leaving you x^2 -17x = -10.
2. then plus 10 to both sides canceling out the negative one giving you... x^2- 17x +10= 0...
3. then plug in to the quadratic equation..yeah..




second problem:
1. minus 5 from both sides... > x^2-3x-8 =0
2. then plug in again to the quadratic equation...
2.

Answer 4

first problem: x^2 - 2x = 15x - 10
x^2 - 17x + 10 = 0
using quadratic formula,
x = [17 + square root of (249)] /2 or
[17 - square root of (249)] /2

x = 16.39 or 0.61

second problem: x^2 - 3x -3 = 5
x^2 - 3x -8 = 0
using quadratic formula,
x = [3 + square root of (41)] /2 or
[3 - square root of (41)] /2

x = 4.70 or -1.70

Answer 5

advantageous Re-write the equation so as that 0 is on the excellent part m^2+2m-8=0 a is the coefficient of the squared term, for that reason m^2, and a=+a million b is the coefficient of the term to ^a million, for that reason 2m, and b=+2 c is the consistent term, and is -8 m {-b+/-rt(b^2-4ac)} / 2a m={-2+/-rt(2^2-4(a million)(-8))} / 2 m= {-2+/-rt(4+32)} / 2 m= {-2+/-rt(36)} / 2 m= {-2+/-6} / 2 m= -8/2 or m=4/2 m=-4 or 2

Answer 6

1st prob:
a=1+(6)^1/2
b= -1-(6)^1/2, where a,b are the roots of the equation.

2nd prob:
{(3)^1/2}_+{(7)^1/2}
----------------------
2/(3)^1/2
are the roots,
all you have to do is to find out the discriminent andthen find the roots using it.
Discriminent is D=(b^2)- 4ac.
If a and b are the roots of the =n, then
a=[(-b)+-{D}^1/2] /2a

Answer 7

first:
rearrange it to
x^2 - 17x +10 =0
then factorised it to
(x-17/2)^2 - (17/2)^2+10=0
(x-8.5)^2 = 8.5^2 -10 = 62.25
x = 8.5+sqrt(62.25) or x = 8.5-sqrt(62.25)

second problem, reaarange:
x^2 -3x -8 =0
and just follow the mathematical tricks above will do.

Answer 8

1.x^2-2x=15x-10
x^2-17x+10=0
x=[17+(289-40)^1/2]/2 ; x=[17-(289-40)^1/2]/2

2.x^2-3x-3=5
x^2-3x-8=0
x=[3+(9+32)^1/2]/2 ;x=[3-(9+32)^1/2]/2

Answer 9

Go to webmath.com