Answer:
81 square inches.
Step-by-step explanation:
Draw a diagram to represent what you know.
You don't know the values of the lengths so represent them algebraically.
You know the perimeter is 45 inches and that the perimeter is calculated by the sum of all of the sides of a shape.
You can rearrange to find the value of a side you've denoted as some unknown variable.
The area is given by the product of the sides. Express this algebraically and then input the value you found.
You can start by subtracting different equations from each other.
3x + 2y + 3z = 1
subtract
3x + 2y + z = 7
2z = -6
divide by 2
z = -3
add the following two expressions together:
3x + 2y + z = 7
3x + 2y + 3z =1
6x + 4y + 4z = 8
subtract the following two expressions:
6x + 4y + 4z = 8
5x + 5y + 4z = 3
x - y = 5
^multiply the whole equation above by 3
3x - 3y = 15
subtract the following two expressions:
3x - 3y = 15
3x + 2y = 10
-5y = 5
divide each side by -5
y=-1
take the following expression from earlier:
x - y = 5
substitute y value into above equation
x - - 1 = 5
2 negatives make a positive
x + 1 = 5
subtract 1 from each side
x = 4
Therefore x = 4, y = -1, z = -3
I checked these with all 3 equations and they worked :)
(it's quite complicated, comment if you don't understand anything) :)
Answer:
The first and the second equation is flipped... meaning you have to switch their places
Step-by-step explanation:
I think I did this before so good luck...
Answer: 15/7 2 1/7
Step-by-step explanation: First divide 8x-3=x+12 Then add 3 to both sides.
8x=x+15 Subtract x from both sides. 7x=15 Then divide again so 7/7 and 15/7. If you simplify it become 2 1/7
