78, divide 390 by 5 which equals 78
4(5x + 7) = 128
First, I'd do distributive property and get:
20x + 28 = 128
Then, subtract 28 from each side.
20x = 100
Next, I'd divide 100 by 20 = 5
x = 5
4 *(5(5) + 7) = 128
5 * 5 = 25
4 * (25 + 7)
4 * 32 = 128
Therefore, the perimeter = 2l + 2w
l = 4
w = 5x + 7
BUT we know that x = 5
w = 5(5) + 7 = 32
2(4) + 2(32)
8 + 64 = 72
Therefore, the perimeter would be 72 inches.
Answer:
4/9
Step-by-step explanation:
12 feet long
1st piece = x
2nd piece = 2x-3
3x-3 =12
3x=15
x = 5
1st piece = 5 feet
2nd piece = 2*5=10-3=7 feet
