Solve by using the quadratic formula. x^2=7x-9?

Answer 1

x^2-7x+9

={-(-7)+/- sqr root [49-4(1)(9)]}/2

={7+/- sqr root 13 }/2

Answer 2

well, first u need to bring the equation into the standerd for ax^2+bx+c=0.
x^2=7x-9
-x^2 on each side
-x^2+7x-9=0
we can solve it many ways, but lets factor the equation. to do this, we need to find a pair of numbers that when added, u get b (+7) and wen u multiply them u get a*c (9).
well, none seem possible, so lets use the formula to solve:
ax^2+bx+c=0
x=(-b +/- √(b^2-4ac))/2a
ur equation is:
-x^2+7x-9=0
thus, a=-1, b=7, c=-9.
x=(-b +/- √(b^2-4ac))/2a
x=(-7 +/- √(7^2-4(-1)(-9)))/(2(-1))
x=(-7 +/- √(49-36))/-2
x=(-7 +/- √(13))/-2
there will be two values of x, the first if which is:
x=(-7+√13)/-2
√(13)= about 3.61
x=(-7+3.61)/-2
x=(-3.39)/-2
x=1.695
the second value will be:
x=(-7-√13)/-2
x=(-7-3.61)/-2
x=(-10.61)/-2
x=5.305
remember that they are estimates.

Answer 3

put it all to one side so x^2-7x +9 = 0
now just use the quadrativ formula to work it out.

x=10.60555 or x= 3.6044

Answer 4

this quadratic equation doesnt work as
a=2 b=-7 c=9
7- or + square root (49-72)
that value in the brackets is -23 and you cannot find the square root of a negative number although i might be doing this the wrong way and getting the wrong value for a

Answer 5

Get it all on the left side:
x² -7x + 9 = 0

So a = 1, b = -7, c = 9

Plug this into the quadratic equation:
....... -(-7) +/- sqrt( (-7)² - 4(1)(9) )
x = ----------------------------------------
....................... 2(1)

....... 7 +/- sqrt( 49 - 36 )
x = ----------------------------
................... 2

....... 7 +/- sqrt( 13 )
x = ----------------------
................. 2