Mohon Bantuannya Pleaseee, jgn lupa sama caranya ya……ada 15 point nih

1. panjang = 2½ = 2,5 kali dari lebar

lebar = ?

luas = 90 cm²

keliling = ?

panjang = P

lebar = L

luas = panjang × lebar

90 cm² = 2,5 L × L

90 cm² = 2,5 L²

90 cm² : 2,5 = L²

36 cm² = L²

√36 = L ( akar pangkat dari 36 )

6 cm = L

panjang = 2,5 L

= 2,5 × 6 cm

= 15 cm

keliling = 2 × ( P + L )

= 2 × ( 15 cm + 6 cm )

= 2 × 21 cm = 42 cm

Jadi, lebar = 6 cm dan keliling = 42 cm

2. a. nilai x = 2x + 5 = 3x – 7

= 2x – 3x = -7 – 5

= -x = -12

= x = 12 cm

b. panjang sisi persegi = 2x + 5 = 3x – 7

= 2 × 12 cm + 5 = 3 × 12 cm – 7

= 24 cm + 5 = 36 cm – 7

= 29 cm = 29 cm

c. Luas = s²

= 29²

= 841 cm²

Keliling = 4 × s

= 4 × 29 cm

= 116 cm

3. panjang = 30 m

lebar = 25 m

harga tanah per m² = Rp600.000,00/m²

Menentukan Luas persegi panjang

Luas = panjang × lebar

= 30 m × 25 m

= 750 m²

harga tanah total = Luas × harga tanah

= 750 m² × Rp600.000,00/m²

= Rp450.000.000,00/m²