I need help with this. Write a quadratic equation having given solutions: -4,7/5
S spel111 New member Joined Jun 25, 2005 Messages 1 Jun 25, 2005 #1 I need help with this. Write a quadratic equation having given solutions: -4,7/5
W wjm11 Senior Member Joined Nov 13, 2004 Messages 1,417 Jun 25, 2005 #2 Write a quadratic equation having given solutions: -4,7/5 Click to expand... Just write the eqn in factored form: (x+4)(x-7/5) = 0
Write a quadratic equation having given solutions: -4,7/5 Click to expand... Just write the eqn in factored form: (x+4)(x-7/5) = 0
S soroban Elite Member Joined Jan 28, 2005 Messages 5,586 Jun 25, 2005 #3 Hello, spel111! Write a quadratic equation having given solutions: -4, 7/5 Click to expand... You already know how to solve a quadratic equation by factoring, right? Well, just run the problem backwards . . . The answers were: . x .= .-4 . . . . . x .= .7/5 Then we have: . x + 4 .= .0 . . . . . 5x .= .7 . . . . . . . . . . . . . . . . . . . . . . . . 5x - 7 .= .0 Multiply the two equations: . (x + 4)(5x - 7) .= .0 . . . . . . . . . . . and we have: . x<sup>2</sup> + 13x - 28 .= .0 . . . . There! If you read up the page, you'll see that it's <u>exactly</u> how we solve a quadratic. .
Hello, spel111! Write a quadratic equation having given solutions: -4, 7/5 Click to expand... You already know how to solve a quadratic equation by factoring, right? Well, just run the problem backwards . . . The answers were: . x .= .-4 . . . . . x .= .7/5 Then we have: . x + 4 .= .0 . . . . . 5x .= .7 . . . . . . . . . . . . . . . . . . . . . . . . 5x - 7 .= .0 Multiply the two equations: . (x + 4)(5x - 7) .= .0 . . . . . . . . . . . and we have: . x<sup>2</sup> + 13x - 28 .= .0 . . . . There! If you read up the page, you'll see that it's <u>exactly</u> how we solve a quadratic. .
