Pre-calculus need help!!

Quadratic Formula
1.) x+6/x=-7
2.) 4x/x+4 + 3/x-1 = 15/x^2+3x-4
3.) x+3/x - 2/x+3 = 6/x^2+3x

formula:
-B+ sqrt B^2 + (-4)(a)(c)/2a
f u only wanted to use the formula it's not necessary though.

please help me! it's going to pass tomorrow!! please!

asked by Isis
  1. your formula should say:
    x = (-b ± √(b^2 - 4ac) )/(2a)

    1. x + 6/x = -7
    each term by x

    x^2 + 6 = -7x
    x^2 + 7x + 6 = 0
    it factors, no need for the formula
    (x+1)(x+6) = 0
    x = -1 or x = -6

    2. you probably meant:
    4x/(x+4) + 3/(x-1) = 15/(x^2 + 3x - 4)
    4x/(x+4) + 3/(x-1) = 15/((x-1)(x+4) )
    multiply each term by (x+4)(x-1) , the LCD
    4x(x-1) + 3(x+4) = 15
    4x^2 - 4 + 3x + 12 = 15
    4x^2 + 3x -7 = 0
    x = (-3 ±√(9-4(4)(-7)) )/8
    = (-3 ±√121)/8 = (-3 ± 11)/8
    x = 1 or x = -7/4

    or.... we could have factored it again
    (x-1)(4x + 7) = 0
    x = 1 or x = -7/4

    3. again, brackets will be essential.
    (x+3)/x - 2/(x+3) = 6/( x(x+3))
    the LCD is x(x+3) , so multiply each term by x(x+3)
    You can take it from there.

    posted by Reiny

Respond to this Question

First Name

Your Response

Similar Questions

  1. Math

    Use the quadratic formula to solve each of the following quadratic equations... 1. 2x^2-5x=3 2. 3x^2-2x+1=0 Rearrange the equation in quadratic formula form. 2x^2 -5x -3 = 0 Then use the formula. Tell me what you don't understand
  2. math,algebra

    can someone help me out factor out this 0=16t^2-122t+180 i have so far this but the last one i am not sure 8(2t^2-14t + ?) you need to use the quadratic formula: -b(+or-)[sqrt(b^2-4ac)/2a] so you are saying that i don't have to
  3. Math

    Solve for the zeros of the function using the quadratic formula. 3x^2=-4x+6 I know what the quadratic formula is but when I put it into the formula I keep getting an error on the graphing calculator.
  4. Calculus

    Please look at my work below: Solve the initial-value problem. y'' + 4y' + 6y = 0 , y(0) = 2 , y'(0) = 4 r^2+4r+6=0, r=(16 +/- Sqrt(4^2-4(1)(6)))/2(1) r=(16 +/- Sqrt(-8)) r=8 +/- Sqrt(2)*i, alpha=8, Beta=Sqrt(2) y(0)=2,
  5. math

    use the quadratic formula to solve this equation. 4x^2-8x+3=5 use the formula x=-b + or - the sqrt of b^2-4ac/2a yes, the 2a divides into all. Memorize it.
  6. math

    15t^2+7t=2 The quadratic formula tells you that the solutions are: t = [-b +/-sqrt (b^2 - 4ac]/ (2a) In this case, a = 15, b = 7 and c = -2 solve the equation for t. What values for t will you get when you substitute the values
  7. Pre-Algebra

    Please help to solve to find x,y 1. y=7x-3 2. 4x+2y=8 Take the value of y in the first formula and substitute it for y in the second formula. Solve the second formula for x. Once x is found, solve for y in the second formula.
  8. Ap algebra

    2+3X^2-X^3=0 by use quadratic formula. The answer of textbook is 3.19 So I solved and came out a wrong answer What I did factor out (-X+3)X^2+2=0 Then By quadratic formula, a=1,b=0,c=2. Thus I got sqrt(8)/2
  9. math-calculus

    solve equation |x^2-2x-6| using quadratic formula. i not get how to do this and it says quadratic formula.
  10. algebra

    I worked the problem out, but could you check my work over and see if it's correct? I used the quadratic formula. 2x^2+10x+11 a=2 b=10 c=11 x=-10(plus or minus) sqrt 10^2-4(2)(11) over 2(2) -10(plus or minus) sqrt 100 - 8(11) over

More Similar Questions