Solve the system of equations.
y= 2x
y= x2 - 15

two solutions : (-3;-6)   ,  (5;10)

Step-by-step explanation:

hello :

the system is : y= 2x (*)

                       y= x2 - 15 (**)

put the value of y use (*) in (**) :

2x = x² - 15

x²-2x-15 = 0

(x+3)(x-5)=0

x+3 =0  or x-5=0

x= -3 or x= 5

case 1 : x= -3    y = 2(-3) = -6

case 2 : x=5    y = 2(5) = 10

two solutions : (-3;-6)   ,  (5;10)