Question

stiint ca b-c=31 si axb-axc=837 calculati a axb-axc=1440 si a=45 calculati b-c
a+b-c=48 si d=144 impartit [95-83] calculati axd+bxd-cxd b-c=7,a=14 b=21 calculati ax[b-c]+axb

Answer 1

1. a*(b-c)=897 -> a=897/31=27

2. a*(b-c)=1440 -> b-c=1440/45=32

3. a+b-c=48
d= 144/12=12
d*(a+b-c)=12*48= 576

4. a*(b-c)+a*b= 14*7 + 14*21= 98+294 =392

Answer 2

a)  b + c = 21  si a = 7

 a × b + a × c = a × ( b + c ) = 7 × 21 = 147

b)  b - c = 31

a × b - a × c = 837

a × ( b - c ) = 837

a × 31 = 837

a = 837 : 31

a = 27

c)   a = 45

a × b - a × c = 1 440

a × ( b - c ) = 1 440

45 × ( b - c ) = 1 440

b - c = 1 440 : 45

b - c = 32

_____________________________

a + b - c = 48   si   d = 144 : 12 ⇒  d = 12

a × d + b × d - c × d =

= d × ( a + b - c ) =

= 12 × 48 =

= 576

_______________________

b - c = 7;   a = 14;  b = 21

a × ( b - c ) + a × b =

= 14 × 7 + 14 × 21

= 14 × ( 7 + 21 )

= 14 × 28 =

= 392