tolong nomor 6 ya kak pakai jalan jg makasih

langsung ya

4×(x+3) = 2×(2x - 3 + x + 1)
4×(x+3) = 2×(3x - 2)
4x + 12 = 6x - 4
4x - 6x = -4-12
-2x= -16
x = -16/-2
x = 8

panjanh sisi persegi = x + 3 = 8 + 3 = 11 cm