Answer:
x=5.5
Explanation:
Perimeter of ABCD=85
The perimeter is everything around the outside added together.
Form an equation:
3x+4+4x+6x-11+5x-7=85
Collect the like terms:
Like terms are terms that have the same powers and coefficient.
3x+4x+6x+5x=18x
4-11-7= -14
Put it back into an equation:
18x-14=85
Do inverse operations to find out what x is:
85+14=99
18x=99
99÷18=5.5 (we divide because, in algebra, when a number is next to a letter, it means times and as we want the inverse, you would have to divide)
x=5.5
Hope this helps :)