Answer:
a = 3.2
Step-by-step explanation:
2( -a - 8) + 7a = 0
-2a -16 + 7a = 0
5a - 16 = 0
5a = 16
a = 16/5
a = 3.2
Answer:
140 feet
Step-by-step explanation:
You will need to find the perimeter of the backyard to find how many feet of fencing will be needed
the formula for perimeter is: 2l+2w
So 2 times 30 is 60
with 2 times 40 80
60+80 is 140
Thus you will need 140 feet to cover the backyard
Hope this helps!
Let the width be X
Then the length is X + 70
The perimeter is the sum of all sides
There are 2 widths (left side and right side) and 2 lengths (top and bottom)
Perimeter = 2 * width + 2 * length
Perimeter = 2 * X + 2 * (X+70)
Perimeter: 2 X + 2 X + 140 = 380
4 X = 380-140
4 X = 240
X = 240 / 4
X = 60
Width = 60 - the smaller of two sides
Length = X + 70 = 60 + 70 = 130 - the larger of two sides
Check:
<span>
2 * 60 + 2 * 130 = 380 </span>
4 2/3 is equal to 4 8/12. 3 and 1/4 is equal to 3 3/12. 4 8/12- 3 3/12 = 1 5/12. 1 1/2 would be a better estimate.
