Question

știind că a = 71 - 72:9; b = 2 x (7 +21): 8; c= 507 – 63 x 8, calculează: c) bx (a +c); a) a:bic - b) 2Xa - 7xC d) (a x b) - (a x c).​

Answer 1

Răspuns:

a = 71 - 72 : 9

a = 71 - 8

a = 63

b = 2 × ( 7 + 21) : 8

b = 2 × 28 : 8

b = 56 : 8

b = 7

c= 507 - 63 × 8

c = 507 - 504

c = 3

b × ( a + c) = 462

7 × ( 63 + 3 ) =

7 × 66 = 462

2 × a - 7 × c = 105

2 × 63 - 7 × 3 =

126 - 21 = 105

( a × b ) - ( a × c ) = 252

( 63 × 7 ) - ( 63 × 3 ) =

441 - 189 = 252

Answer 2

______________________

a=71-27÷9

a=71-8

a=63

_______________________

b=2•(7+21)÷8

b=2×28÷8

b=56÷8

b=7

_______________________

c=507-63•8

c=507-504

c=3

_______________________

2•a-7•c=105

=2•63-7•3

=126•21

=105

_______________________

(a•b)-(a•c)=256

• { vom înlocui }

(63•7)-(63•3)

441-189

=256

_______________________