Question

układy równań kto to potrafi a działanie takie

{8a + 9x = 36

{ 13k + l = 15

{6a - 21x = 228

{a-12x=21

Answer 1

{6a - 21x = 228

{a - 12x = 21

 

{6a - 21x = 228

{a = 21 + 12x

 

{6( 21 + 12x)- 21x =228

{a = 21 + 12x

 

{126 + 72x - 21x = 228

{a = 21 + 12x

 

{72x - 21x = 228 - 126

{a = 21 + 12x

 

{51x = 102 | : 51

{ a = 21 + 12x

 

{ x = 2

{ a = 21 + 12·2

 

{ x = 2

{ a = 21 + 24

 

{x = 2

{ a = 45