Use the area of rectangle formula which is:
Given that:
- area of rectangle = 16
- width = 8
- length = x-5
Substitute in the formula:
Distribute 8 in the expression:
Move -40 to another side and change from -40 to 40.
Then move 8 to divide 56, leaving only x.
Hence, the answer is:
4 x^2 + 20 x + 25 = 7
Divide both sides by 4:
x^2 + 5 x + 25/4 = 7/4
Write the left-hand side as a square:
(x + 5/2)^2 = 7/4
Take the square root of both sides:
x + 5/2 = sqrt(7)/2 or x + 5/2 = -sqrt(7)/2
Subtract 5/2 from both sides:
x = sqrt(7)/2 - 5/2 or x + 5/2 = -sqrt(7)/2
Subtract 5/2 from both sides:
Answer: x = sqrt(7)/2 - 5/2 or x = -5/2 - sqrt(7)/2
Answer:
12 square cm correct to 2 significant figures
Step-by-step explanation:
Area of a Rectangle = L X B = 2.1 X 5.6 = 11.76 square cm
To round your result to 2 significant figure, we start counting from the left from the first non-zero digit.
The first two digits are 11 but because the number after is 7 (greater than 4), we round up to 12.
11.76 square cm = 12 square cm correct to 2 significant figures
8 + 13 + 14 + 7 = 42
Chinese = 8/42
Simplified = 4/21
