Question

Temat (równania kwadratowe)
zad.12.5(zbiór zadań)
b) (x-1)'kwadrat' = 26-2x,
c) (x+1)'kwadrat'+(x-1)'kwadrat'=20
e) y(y-15)=3(108-5y),
f)51-z(3z+4)=2(17-2z)-58

Answer 1

B) (x-1)²= 26-2x
x²-2x+1=26-2x
x²=25
x=5

c) (x+1)²+(x-1)²=20
x²+2x+1+x²-2x+1=20
2x²+2=20
2x²=18
x²=9
x=3

e) y(y-15)=3(108-5y)
y²-15y=324-15y
y²=324
y=18

f)51-z(3z+4)=2(17-2z)-58
51-3z²-4z=34-4z-58
-3z²-4z+51=-4z-24
-3z²=-75
3z²=75
z²=25
z=5