Resposta:
Primer rectangle:
Amplada = 11
Longitud = 14
Segon rectangle:
Amplada = 12
Longitud = 15
Tercer rectangle:
Amplada = 13
Longitud = 16
Explicació pas a pas:
Donat que:
Primer rectangle:
Amplada = x
Longitud = x + 3
2n rectangle:
Augment de la dimensió d'1 cm respecte al primer rectangle;
Amplada = x + 1
Longitud = x + 4
3r rectangle:
Augment de la dimensió de 2 cm respecte al primer rectangle;
Amplada = x + 2
Longitud = x + 5
Suma dels tres perímetres del rectangle:
Perímetre d'un rectangle: 2 (l + O)
Primer rectangle:
2 (x + x + 3) = 2 (2x + 3) = 4x + 6
2n:
2 (x + 1 + x + 4) = 2 (2x + 5) = 4x + 10
3r:
2 (x + 2 + x + 5) = 2 (2x + 7) = 4x + 14
Suma de perímetres = 162
(4x + 6 + 4x + 10 + 4x + 14) = 162
12x + 30 = 162
12x = 162 - 30
12x = 130
x = 11
Per tant,
Primer rectangle:
Amplada = 11
Longitud = 11 + 3 = 14
2n rectangle:
Amplada = 11 + 1 = 12
Longitud = 11 + 4 = 15
3r rectangle:
Amplada = 11 + 2 = 13
Longitud = 11 + 5 = 16
Answer:
Dependent variable is the amount of hours of sleep.
Independent variables are gender, amount of time spent studying, and hours of activity.
The 3 it is the one the bottom left corner
Answer:
x = 5/39
, y = 539/39
Step-by-step explanation:
Solve the following system:
{y - 2.5 x = 13.5
12.25 x - y = -12.25
In the first equation, look to solve for y:
{y - 2.5 x = 13.5
12.25 x - y = -12.25
y - 2.5 x = y - (5 x)/2 and 13.5 = 27/2:
y - (5 x)/2 = 27/2
Add (5 x)/2 to both sides:
{y = 1/2 (5 x + 27)
12.25 x - y = -12.25
Substitute y = 1/2 (5 x + 27) into the second equation:
{y = 1/2 (5 x + 27)
1/2 (-5 x - 27) + 12.25 x = -12.25
(-5 x - 27)/2 + 12.25 x = 12.25 x + (-(5 x)/2 - 27/2) = 9.75 x - 27/2:
{y = 1/2 (5 x + 27)
9.75 x - 27/2 = -12.25
In the second equation, look to solve for x:
{y = 1/2 (5 x + 27)
9.75 x - 27/2 = -12.25
9.75 x - 27/2 = (39 x)/4 - 27/2 and -12.25 = -49/4:
(39 x)/4 - 27/2 = -49/4
Add 27/2 to both sides:
{y = 1/2 (5 x + 27)
(39 x)/4 = 5/4
Multiply both sides by 4/39:
{y = 1/2 (5 x + 27)
x = 5/39
Substitute x = 5/39 into the first equation:
{y = 539/39
x = 5/39
Collect results in alphabetical order:
Answer: {x = 5/39
, y = 539/39
