You are given a rectangle and are told that the length is 1 cm more than twice the width of the rectangle. The area of the rect. is also given, and is 21 cm^2.
Find the length and width. To do this, represent the length by y and the width by x. Then "1 cm more than twice the width" comes out to y=2x+1 (cm).
Since the area of a rect. is equal to the product of its length and width,
x(2x+1)=21 cm^2. Multiply out x(2x+1). show your work. Next, subtract 21 from both sides. Write your algebraic expression on the left side as a quadratic equation in standard form.
Solve this quadratic equation for x. Recall that x (in cm) will represent the width of the rect., and y=2x+1 (in cm) will repr. the length.
Answer:
10,000
Step-by-step explanation:
"The number who have been vaccinated against both is twice the number who have been vaccinated only against mumps."
Let b = number of children vaccinated against both.
Let m = number of children vaccinated only against mumps.
b = 2m
"If 5,000 have been vaccinated against both"
5000 = 2m
m = 2500
5000 children are vaccinated against both.
2500 children are vaccinated only against mumps.
The total number vaccinated against mumps is the number vaccinated only against mumps plus the number vaccinated against both:
2500 + 5000 = 7500
"the number of children who have been vaccinated against rubella is twice the number who have been vaccinated against mumps."
total number of children vaccinated against rubella = 2 * 7500 = 15,000
5000 of those children are vaccinated against both.
15,000 - 5000 = 10,000
10,000 children are vaccinated only against rubella.
Answer: 10,000
True
I’m not 100% positive but I’m pretty sure
3 (x-7) = 9
X-7 = 3
X = 10
B is the answer
