Question

а) 25х²=20x-4

b)2x=15-x²




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Answer 1

a) 25x² = 20x -4

25x² -20x +4

Δ= b²-4ac

Δ= (-20)² -4.25.4

Δ= 400 -400

Δ= 0

x= -b +/- √Δ / 2a

x= -(-20) +/- √0 / 2.25

x'= 20 / 50 (simplificando por 2).

x'= 10/25 (simplificando por 5).

x'= 2/5

x''= 2/5

b) 2x=15-x²

x²+2x-15=0

D=(2)²-4.(1).(-15)

D=4+60 = 64

x= -(2) +-8

       2.(1)

x¹=-2+8/2 = 6/2 = 3

x²=-2-8/2 = -10/2 = -5