Question

Pls exercitiul 13.Dau coroana...

Answer 1

a) 312 × 9 + 288 ×9 + 100 × 9 =
=9 × (312 + 288 + 100)
=9 × 700
= 6 300

b) 2005 × 2004 + 2005 × 1 - 2005 × 2005 +
= 2005 × ( 2004 + 1 - 2005 )
= 2005 × 0
= 0

c) 2001 × 1999 - 1999 - 2000 ×1998 =
= 1999 × (2001 - 2000 × 1998 )
= 1999 × ... Aici nu am stiut.

d) 2007 × 204 + 2007 × 796 - 1000 × 2007 =
= 2007 × (204 + 796 - 1000)
= 2007 × 0
= 0

e) 1005 × 1004 + 1005 × 15 - 1005 × 19 =
= 1005 × (1004 + 15- 1005)
= 1005 × 14
= 14 070

f) 315 × 301 - 315 × 299 - 315 =
= 315 × (301 - 299) 
= 315 × 2
= 630

g) 15 × 201 - 15 × 199 - 15 =
= 15 × ( 201 - 199)
= 15 × 2 
= 30

h) 214 × 402 - 214 × 399 - 214 =
= 214 × ( 402 - 399)
= 214 × 3
= 642

i) 1991 × 1990 - 1991 × 1989 =
= 1991 × (1990 - 1989)
= 1991 × 1
= 1991

j) 990 × 95 - 79 × 990 - 16 × 990 =
= 990 × ( 95 - 79 - 16)
= 990 × 0
= 0

k) 90 × 42 - 25 × 90 - 7 × 90 =
= 90 × ( 42 - 25 - 7 )
= 90 × 10
= 900

l) 87 × 52 - 39 × 87 - 12 × 87 =
= 87 × (52 - 39 - 12)
= 87 × 1
= 87 

Succes si spor la scris!