Title: What is the solution of the linear-quadratic system of equations? Post by: nurul_me0w21 on Nov 29, 2012 y=x^2+5x-3
y-x=2 another question if you know it is: What are the solutions of the quadratic equation? 2x^2-16x+32=0 i dont want just answers. I actually would like to be able to understand how to do them. It would be much appreciated! Title: What is the solution of the linear-quadratic system of equations? Post by: _coco_ on Nov 29, 2012 1.Equation 1: y=x^2+5x-3 Equation 2: y-x=2
First step is to solve equation 2 for y, so you have y=x+2 Next you can sub in your equation 2 for the y in equation 1 so you have x+2=x^2+5x-3 Now you can subtract an x and a 2 from both sides to get the left side equal to zero. That gives you 0=x^2+4x-5 Now you can factor it to 0=(x+5)(x-1) Last, you solutions are x=-5,x=1 2. 2x^2-16x+32=0 First factor out a 2 so you have 2(x^2-8x+16)=0 The you can factor the inside to (x-4)(x-4) so you have 2(x-4)(x-4)=0 So your solution is only x=4 Hope that helps. Title: What is the solution of the linear-quadratic system of equations? Post by: julie.t on Nov 29, 2012 y=x^2+5x-3
y-x=2 Substitute y. x^2+5x-3-x=2 Add common factors. x^2+4x-3=2 Subtract 2 from both sides of the equation. x^2+4x-5=0 Quadratic Formula: [-4±?4²-(4*1*-5)]/(2*1)=0 [-4±?16-(-20)]/2=0 [-4±?36]/2=0 [-4±6]/2=0 (-4+6)/2 2/2 x=1 (-4-6)/2 -10/2 x=-5 Answer: x=1 or x=-5 __________ 2x^2-16x+32=0 Quadratic Formula: (-b±?b²-4ac)/2a=0 [16±?-16²-(4*2*32)]/(2*2)=0 [16±?256-(256)]/4=0 [16±?0]/4=0 [16±0]/4=0 (16+0)/4 16/4 x=4 (16-0)/4 16/4 x=4 Answer: x=4 Title: What is the solution of the linear-quadratic system of equations? Post by: julie777 on Nov 29, 2012 second equation: y-x = 2 can be written as y= 2+x
Substituting this in the first equation, 2 + x = x^2 + 5x -3 bringing all like terms together, 2 + 3 = x^2 + 5x - x 5 = x^2 + 4x Now, to find the value of x , equate the polynomial to zero. x^2 + 4x -5 = 0 ---------> factors of -5 are = 5, 1 but we must satisfy the equation which has a negative 5 and a positive 4 so, the signs for our factors 5 and 1 would be (+5,-1) x^2 + 5x - 1x -5 =0 x( x +5) - 1 (x +5) = 0 (x+5) (x-1) = 0 x = -5 or x = 1 Hope that helps! |