Pada persegi ABCD, panjang AC =(2x+9) cm dan BD= ( 4x-7) .luas persrgi tersebut adalah..

AC=BD
2x+9 = 4x-7
2x-4x = -7-9
-2x = - 16
x= 8

AC = BD = 2x+9 = 2(8)+9 = 16+9 = 25

AB=CD
AB² = 25
AB= akar 25
AB=5

Luas = 5² = 25 cm²

Caranya=
1. 4x-7=2x+9 = 4x-7+7 = 2x+9+7 = 4x = 2x+16 = 4x-2x = 16 = 2x=16 x= 16;2 = 8
l= sxs = 5x5 = 25 cm2 
Maaaf kalo salah