Solve the system of equations If there is no solution enter
Solve the system of equations. (If there is no solution, enter NO SOLUTION.) {y = 2x^2 - x + 4 y = x^2 + 3x + 9 (x, y) = () (smaller x-value) (x, y) = () (larger x-value)
Solution
y = 2x^2 -x +4 ----(1)
y = x^2 +3x +9 ----(2)
Equate equation 1 and 2:
2x^2 -x +4 = x^2 +3x +9
x^2 -4x -5 =0
factorise : x^2 -5x +x -5 =0
x(x-5) 1+(x-5) =0
(x+1)(x-5) =0
x= -1 ; x=5
So, y = x^2 +3x +9
plug x = -1 ; y = (-1)^2 -3 +9 = 7
x=5 ; y=5^2 -3*5 +9 =19
So, Solution set : smaller set ( -1, 7)
larger set (5 , 19)
