Question

Sebuah persegi panjang dgn ukuran panjang(3x+7)cm, lebar(2x+3)cm dan keliling 50cm.luas persegi panjang tsb adalh

Answer 1

Diketahui :
K = 50 cm
p = (3x +7)
l = (2x +3)

Dijawab :
K = 2(p +l)
50 = 2{(3x +7) +(2x +3)}
50 = 2(5x +10)
50 = 10x +20
50 -20 = 10x
30 = 10x
x = 30/10
x = 3

Maka,
p = 3x +7
p = 3(3) +7
p = 9 +7
p = 16

l = 2x +3
l = 2(3) +3
l = 6 +3
l = 9

Maka
Luas = p .l
       = 16 . 9
       = 144 cm²

Itu jawabannya.

Answer 2

K = 2(p+l)
50 = 2(3x+7+2x+3)
50/2 = 5x+10
25-10 = 5x
15 = 5 x
x = 15/5 = 3

L = p.l = (3.3+7) (2.3+3) = 16 x 9 = 144 cm²