Răspuns :
[ ( 38 × a + 120 ) : 25 × 54 ] - 980 = 100
[ ( 38 × a + 120 ) : 25 × 54 ] = 100 + 980
[ ( 38 × a + 120 ) : 25 × 54 ] = 1080
[ ( 38 × a + 120 ) : 25 ] = 1080 : 54
[ ( 38 × a + 120 ) : 25 ] = 20
[ ( 38 × a + 120 ) ] = 20 × 25
[ ( 38 × a + 120 ) ] = 500
38 × a = 500 - 120
38 × a = 380
a = 380 : 38
a = 10
[ ( 38 × a + 120 ) : 25 × 54 ] = 100 + 980
[ ( 38 × a + 120 ) : 25 × 54 ] = 1080
[ ( 38 × a + 120 ) : 25 ] = 1080 : 54
[ ( 38 × a + 120 ) : 25 ] = 20
[ ( 38 × a + 120 ) ] = 20 × 25
[ ( 38 × a + 120 ) ] = 500
38 × a = 500 - 120
38 × a = 380
a = 380 : 38
a = 10
Răspuns:
Explicație pas cu pas:
[ ( 38 × a + 120 ) : 25 × 54 ] - 980 = 100
( 38 × a + 120 ) : 25 × 54 = 100 + 980
( 38 × a + 120 ) : 25 × 54 = 1 080
38 × a + 120 = 1 080 : 54 × 25 → aplic metoda mersului invers
38 × a + 120 = 20 × 25
38 × a + 120 = 500
38 × a = 500 - 120
38 × a = 380
a = 380 : 38
a = 10 → numarul