Tolomg dijawab (A+b-c)^2

(a+b-c)"
= (a+b-c)(a+b-c)
= a" +ab - ac +ab +b" -bc -ac -bc +c"
= a" + b" +c" +ab +ab -ac -ac + bc - bc
= a" + b" + c" + 2ab - 2ac

semoga membantu.......

(a + b - c)^2
(a + b - c)(a + b - c)