tolong di hawab ya jgn lupa pakai cara

diketahui :
∆abc a = 2x+4 , b = 4x-2 , c = 4x+2 , k∆abc = 84

penyelesaian
k = a+b+c
84 = (2x+4)+(4x-2)+(4x+2)
84 = (2x+4x+4x)+(4-2+2)
84 = 10x + 4
84-4= 10x
80/10 = x
8 = x

a = 2x+4
a = 2(8)+4
a = 16+4
a = 20

b = 4x-2
b = 4(8)-2
b = 32-2
b = 30

c = 4x+2
c = 4(8)+2
c = 32+2
c = 34