Answer:
D for the first one and the second one
Step-by-step explanation:
i learned this trust me
Answer:
ABCD is a rhombus
Step-by-step explanation:
Sides AB and DC are opposite and equal in parallelogram ABCD. This means ...
AB = CD
2x +1 = 3x -11
12 = x . . . . . . . . add 11-2x to both sides
Sides AB and CD have length ...
2x +1 = 2(12) +1 = 24 +1 = 25
Then the length of side AD is ...
AD = x +13 = 12 +13 = 25
Adjacent sides AB and AD of the parallelogram have the same length, The figure is a rhombus.
Answer: 
Step-by-step explanation:
The perimeter of a rectangle can be calcualated with this formula:

Where "l" is the lenght and "h" is the height.
The area of a rectangle can be found with this formula:

Where "l" is the lenght and "h" is the height.
In this case we know that:

Therfore, we can susbsitute them into
and solve for "h" in order to find its value:

Find two number whose sum is 3 and whose product is -40. These are -5 and 8. Then, factorizing, we get:

The positive value is the height. Then:

Since the length is 3 centimeters greater than its height, we get that this is: Then:

Substituting values into
, we get that the perimeter is:

Answer:
-a+-2b+4c
Step-by-step explanation:
Combine like terms
-4a+ 3a= -a
b+ -3b= -2b
3c+ c= 4c