College placement test i forget how to do this
Find the solution set to -2/x= x+3 Thanks
2007-08-07 05:47:51 · 3 answers · asked by Anonymous in Science & Mathematics ➔ Mathematics
multiply the x in the denominator
x^2 + 3x = -2
then move the -2 over
x^2 + 3x + 2 = 0
then factor/ use quadratic equation to solve for x.
test your answers to see if what you arrived at works as a solution by subbing x back into the original equation.
2007-08-07 05:52:25 · answer #1 · answered by (+_+) B 4 · 0⤊ 0⤋
Ö¹Multiply both sides by x (cannot be zero!!!)
-2 = x^2 + 3x // add 2 , switch sides
x^2 + 3x + 2 = 0 // I will not even bother completing the square
(x + 1)(x + 2) = 0
Cheking the solutions x in {-1, -2}
-2/-1 = -1 + 3 ?
2 = 2 Yes!
-2/-2 = -2+3 ?
1 = 1 Yes!
2007-08-07 12:55:34 · answer #2 · answered by Amit Y 5 · 0⤊ 0⤋
-2/x = x+3
cross multiplys
-2 = x(x + 3)
distribute
-2 = x^2 + 3x
add 2 for both sides
x^2 + 3x + 2 = 0
factor. Find to numbers that multiply to 2 and add to 3
the two numbers are 1 and 2
(x + 1) (x + 2) = 0
x = -1 or -2
2007-08-07 12:56:20 · answer #3 · answered by 7 · 0⤊ 0⤋