Răspuns :
a + b = 133
a - b = 47
--------------- ( + )
2×a = 180
a = 180 : 2
a = 90
b = 133 - 90 = 43
Verificare:
90 + 43 = 133
90 - 43 = 47
a - b = 47
--------------- ( + )
2×a = 180
a = 180 : 2
a = 90
b = 133 - 90 = 43
Verificare:
90 + 43 = 133
90 - 43 = 47
[tex]a + b = 133 \\ \\ a - b = 47 = > a = b + 47 \\ \\ = = = = = = = = = = = = = = = = \\ \\ b + 47 + b = 133 \\ \\ 2 \times b + 47 = 133 \\ \\ 2 \times b = 133 - 47 \\ \\ 2 \times b = 86 \\ \\ b = 86 \div 2 \\ \\ b = 43 \\ \\ a = 43 + 47 \\ \\ a = 90 \\ \\ => \boxed {a=90} \\ \\ => \boxed {b=43}[/tex]