Question

Solve x2 – 3x = –8

Answer 1

\[x^2 – 3x = –8 \]\[x^2 – 3x + 8 = 0 \]

Answer 2

this is the general form of a quadratic. I don't think you can complete the square so you will have to use the quadratic formula. Are you familiar with that?

Answer 3

answers:
x = 3 +-isqrt29 / 2

x = 3 +-isqrt23 / 2

x = -3 +-isqrt29 / 2

x = -3 +-isqrt23 / 2

Answer 4

Not asking you for the answer choices.....I'm asking if you know how to use the quadratic formula

Answer 5

no

Answer 6

this is the quadratic formula for the quadratic equation\[\begin{array}{*{20}c} {x = \frac{{ - b \pm \sqrt {b^2 - 4ac} }}{{2a}}} & {{\rm{when}}} & {ax^2 + bx + c = 0} \\ \end{array}\]

this is your equation.
\[x^2–3x+8=0\]

Answer 7

all we want to do is find out what a b and c are in order to plug it into the left formula and solve for x.

Answer 8

I'll tell you how to solve it if you can tell me what a b and c are for your equation.

Answer 9

a = x^2 b = 3x c = -8

Answer 10

no a is left of x and since there is no number we use 1
b is also the number next to x in 3x so it will be 3.....can you rewrite it again?

Answer 11

a =3x b = 1 c = -8

Answer 12

nope\[x^2–3x+8=0\]\[ax^2+bx+c=0\]

we know c=8 but can you tell me what a and b are?

Answer 13

sorry c=-8

Answer 14

a = x^2 b = 3x

Answer 15

a b and c have no x's

Answer 16

a - 1 b = 3

Answer 17

a=1

Answer 18

sorry a = 1

Answer 19

\[a=1,b=-3,c=-8\]now we just plug in the values for the formula below \[{x = \frac{{ - b \pm \sqrt {b^2 - 4ac} }}{{2a}}}\]\[{x = \frac{{ 3 \pm \sqrt {(-3)^2 - 4*1*-8} }}{{2*1}}}\]


\[\pm \]
this sign means that you have to do it twice once for + and another time for -
this makes total sense because we are suppose to get two answers for x. So just do it twice and you should be able to get the answer