given function f(x)=x2 -6x+8, find x, if f(x)=3?

f(x)= 2x -6x +8

f(3)= (3)(2) -6(3) +8

f(3)= 6 -18 +8

f(x)= -4

You just plug in 3 everywhere it says “x”. You don’t need to do anything with the left side of the equation.

By the way, the first guy is wrong. Sorry to burst his bubble…

f of x = x^2-6x+8 (the upward carrot is the correct way to display an exponent) if f of x is 3 (f of x is another way to say “y” in quadratic equations)

3=x^2-6x+8

subtract 3

0= x^2 – 6x + 5

find master product (last number multipled, middle added)

0 = (x-1)(x-5) [(-1)(-5)= 5 and -1 + -5 = -6]

solve for each eqation

x-1 = 0 then x = 1

x -5 = 0 then x= 5

solution set is x=1,5

First you’re arranged to make the equation equivalent 0. x^2 – 6x + 8 = 0 then you could desire to component by utilising way of the decomposition technique. to objective this you’re arranged to locate the climate of 8 that upload as much as -6. they’re -2 and -4. Now you’re arranged to place in writing 2 units of brackets with an x in each and each physique and -2 in one and -4 contained in diverse. (x – 2)(x – 4) = 0 Now take each and each component and scientific preserve the variable. x – 2 = 0 x = 2 x – 4 = 0 x = 4 consequently the innovations are 2 and four.

If f[x] = 3, then x^2-6x+8 = 3. Navy b is right

plug in 3 for f(x)

3 = x^2 – 6x + 8

0 = x^2 – 6x + 5

0 = (x – 1) (x – 5)

x = 1 or 5

EDIT:

no, no, no….! the question says find “x” given that f(x) = 3

so you need to plug 3 for f(x)