What number is x in equation x squared plus 3x equals 7?

Answer 1

x^2 + 3x = 7

There is no integer value that can answer this question x=1 yields the inequality 5= 7 and x=2 yields the inequality 10 = 7.

This can be rewritten as x^2 + 3x - 7 = 0.

Using the quadratic equation and substitution we get

X -3 + (3^2 -4*1*(-7))^(1/2)

x= -----------------------------------

X 2*1

x=(-3 +/- (9-28)^(1/2))/2

X -3 +/- (-19)^(1/2)

x=-----------------------

X 2

Since we are taking the square root of a negative number we change the sign and put a -i in front.

X -3 +/- -i(~4.35)

x= ---------------------

X 2

X -3 -/+ 4.35i

x=---------------

X 2

x can be either -1.5 - 2.175i or -1.5 + 2.175i