Question

1. Oblicz wartość wyrażenia 5x2(do kwadratu) - y dla :

a) x = 3 , y = 2

b) x = 5 , y = - 3

c) x = 0,5 , y = 1/3 (jedna trzecia)

d) x = - 1/4 (jedna czwarta) , y = 1/5 (jedna piąta)

e) x = 0 , y = - 12

f) x = -2 , y = 20

Answer 1

a) 5*3^2-2=5*9-2=64-2=62

b) 5*5^2-(-3)=5*25+3=125+3=128

c) 5*0,5^2-1/3=5*0,25-1/3=5/4-1/3=15/12-4/12=11/12

d) 5*(-1/4)^2-1/5=5*1/16-1/5=5/16-1/5=25/80-16/80=9/80

e) 5*0^2-(-12)=0+12=12

f) 5*(-2)^2-20=5*4-20=20-20=0

 

[^] znaczy "do potęgi"

Answer 2

5x²-y

a) x=3, y=2

5*3²-2=5*9-2=45-2=43

 

b) x=5, y=-3

5*5²-(-3)=5*25+3=128

 

c) x=0,5, y=⅓

5*(0,5)²-⅓=5*0,25-⅓=1,25-⅓=125/100-⅓=375/300-100/300=275/300=11/12

 

d)x=-¼, y=⅕

5*(-¼)²-⅕=5*1/16-⅕=5/16-⅕=25/80-16/80=9/80

 

e)x=0, y=-12

5*0-(-12)=0+12=12

 

f)x=-2, y=20

5*(-2)²-20=5*4-20=20-20=0