Solve please?

Question

85 = 13.06x - 1.9x2

x2 means "x" squared.

Answer 1

Put all terms on one side and then use the quadratic solution to find values for x.

85 = 13.06x - 1.9x2
=> 1.9x^2 -13.06x +85 = 0

Now in the form of ax^2 +bx +c =0

Solutions are x = [-b +/- √(b^2 - 4ac)]/2a

So x=[-(-13.06) +/- √(13.06^2 -4*1.9*85)]/(2x1.9)

=> x=[13.06 +/- √(170.5636 - 646)]/3.8

=> x=[13.06 +/- 21.81i]/3.8 (where i=√(-1))

=> x=3.44 +/ - i.5.74

If you were really not expecting an imaginary number as a solution - then I suggest you check to make sure you have written down the first equation properly (i.e. that it is definitely 85 and not 8.5).

If you discover you did make a mistake in writing down the solution then just follow these steps through with the correct values for a, b and c - the method will not change.

Answer 2

Just use the quadratic formula

(-b+/-sqrt(b^2-4ac))/2a

-13.06+/-sqrt((-13.06)^2-4*-1.9*-85))/-3.8

3.436842105-/+i5.7380274ans.

Answer 3

1.9 x ² - 13.06 x + 85 = 0
x = [ 13.06 ± √(13.06 ² - 646) ] / 3.8
x = [13.06 ±√(- 475.4)] / 3.8
x = [13.06 ± i (21.8) ] / 3.8
x = 3.44 ± i (5.74)

Answer 4

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