Question

lungimea laturii unui patrat este cu20cm mai mica decit jumatatea perimetrului patratului.Aflati lungimea laturii

Answer 1

$P=4l$

$l=\frac{P}{2}-20cm$

$l=\frac{4l}{2}-20cm$

$l=2l-20cm$

$2l-l=20cm$

$l=20cm$

Answer 2

l = P/2 - 20
P = 4 * l
l = 4 * l/2 - 20
2 * l = 4 * l - 40
2 l - 4 l = - 40
- 2 l = - 40
l = 40 : 2
l = 20 cm
P = 4 * 20
P = 80 cm