Question

Dacă a + b +c =198. b-c=123 2-a +b +3 c =?

Answer 1

a + b + c = 198;   b - c = 123

Din relatia:   b - c = 123 deducem ca:   b = c + 123

a + b + c = 198

a + ( c + 123 ) + c = 198

a + 2 x c = 198 - 123

a + 2 x c = 75

_________________

2 a + b + 3 c = 273

= 2 a + c + 123 + 3 c =

= 2 a + 4 c + 123 =

= 2 ( a + 2 c ) + 123 =

= 2 × 75 + 123 =

= 150 + 123 =

= 273

Answer 2

a+b+c=198

c=b+123

a+2b+123=198

a+2b=198-123=75

a+2b=75

75/=25

a=25

b=123+25=148

c=25

2a+b+3c

2x25+148+3x25 =50+148+75=273