Question

afla necunoscuta: 20-a×3=32:4; 45-27+(6xc); b:9+515:5=7×8×2; (d-2)×6+2×(7-5)×6-30=;​

Answer 1

Explicație pas cu pas:

a)20-a×3=8

20-a=8×3

20-a=24

a=24-20

a=4

b)b:9+103=112

b:9=112-103

b:9=9

b=9:9

b=1

c)(d-2)×6+2×(2×7-2×5)×6-30=

(d-2)×6+2×4×6-30=

(d-2)×6+48-30=

(d-2)×6+18

Answer 2

Explicație pas cu pas:

20 - a × 3 = 32 : 4

20 - a × 3 = 8

a × 3 = 20 - 8

a × 3 = 12

a = 12 : 3

a = 4

b : 9 + 515 : 5 = 7 × 8 × 2

b : 9 + 103 = 112

b : 9 = 112 - 103

b : 9 = 9

b = 9 : 9

b = 1

45 - 27 + ( 6 × c ) = 36

( 6 × c ) = 45 - 27

6 × c = 18

c = 18 : 6

c = 3

( d - 2 ) × 6 + 2 × ( 7 - 5 ) × 6 - 30 = 150

( d - 2 ) × 6 + 2 × 2 × 6 - 30

( d - 2 ) × 6 + 24 - 30

( d - 2 ) × 6 = 30 - 24

( d - 2 ) × 6 = 6

d - 2 = 6 : 6

d - 2 = 1

d = 2 + 1

d = 3