tolong sama caranya ya

a.(3x-1)^{2x+5} =(3x-1)^{x+2}
2x+5= x+2
2x-x=2-5
x= -3

b.(x+5)^{7-x }= .(x+5)^{x^2-5}
7-x= x^2-5
-x^2-x+7+5=0
(kali minus 1)
x^2+x-12= 0
(x+4)(x-3)
x= -4 v x=3