Question

Rozwiąż równania:
a) (3x-1)(4x+5)=(4x+5)=(x+5)(2x-1)
b) x do potegi2 -10x+15=0

Answer 1

A) (3x-1)(4x+5)=(4x+5)=(x+5)(2x-1)

3x-1=0 4x+5=0 4x+5=0 x+5=0 2x-1=0
3x=1/3 4x=-5/4 4x=-5/4 x=-5 2x=1/2
x=3 x=-5/4 x=-5/4 x=1/2


x do potegi2 -10x+15=0
a=1 b=-10 c=15
delta= b do kwadratu - 4*a*c
delta=(-10)do kwadratu - 4*1*15
delta= 100-60
delta=40
x1=-b - pierwiastek z delty/ 2a x2=-b + pierwiastek z delty/2a
x1=-(-10)-40/2*1 x2=-(-10) + 40/2*1
x1=10-40/2 x2=10+40/2
x1=-30/2
x1=-15 x2=50/2
x2=25