Luas belah ketupat 96 cm, panjang diagonalnya (3x + 1) cm dan 12 cm, nilai x adalah

d1 = (3x + 1) cm
d2= 12 cm

L. belah ketupat = 96 cm²
1/2 x d1 x d2 = 96
1/2 (3x + 1) (12) = 96
6 (3x + 1) = 96
18x + 6 = 96
18x = 96 - 6
18x = 90
x = 90/18
x = 5 cm

L = d1 × d2 ÷ 2
96 = (3x+1) × 12 ÷ 2
96 = (3x+1 ) × 6
96 = 18x + 6
96 - 6 = 18x
90 = 18x
x = 5

panjang Diagonal 1
3x+1
3(5)+1
15+1
16 cm

semoga bisa membantu