Question

pe b si c ultimele acum va rog

Answer 1

x^4-a²+2ab-b²=0
x^4-(a+b)²=0
x^4=(a+b)²
x²=a+b
x=√a+b
c)x²-x-12=0
x(x-1)=12
x=12
x-1=12
x=12+1
x=13