A + B = 76 A - B = 18 A ÷ B = ???

A + B = 76
A - B = 18
__________-
---- 2B = 58
----- B = 29

b = 29 Subtitusi ke

A + B = 76
A + 29 = 76
A = 76 - 29
A = 47

jadi

A ÷ B = 47/29

A + B = 76
A = 76 - B

subsitusi
A - B = 18
76 - B -B = 18
76 - 2B = 18
-2B = 18 - 76
-2B = -58
B = -58/-2
B = 29

subsitusi
A = 76 - 29 = 47

A : B = 47/29