Question

2x elevado a 2 +4x -70=0

Answer 1

2x²+4x-70 = 0 :2

x²+2x-35 = 0

∆=2²-4.1.(-35)

∆=4+140

∆=144

x'=-2+√144/2.1 =-2+12/2 =10/2 = 5

x"=-2-√144/2.1 =-2-12/2 = -14/2 = -7

S={ -7 ; 5 }