Answer:
D
Step-by-step explanation:
Use the general formula of quadratic equation:
Thus we choose D
Probability works for any given number, so we will assume there are 100 students. Of those 100, 85 of them studied. Since 75% of 85 students passed, we will multiply 85 by 0.75. This gives us 60. So of the students who studied, 60 of them passed. Of the 15 students that didn’t study, 30 percent passed. So we multiply 15 by 0.3. This gives us 4.5 students. Add up 60 and 4.5, and you get 64.5. The probability of passing is 64.5%. If you want to round up, it would be 65%. If you want to round down, it would be 64%. But the most precise answer is 64.5%.
This question is solved applying the formula of the area of the rectangle, and finding it's width. To do this, we solve a quadratic equation, and we get that the cardboard has a width of 1.5 feet.
Area of a rectangle:
The area of rectangle of length l and width w is given by:
w(2w + 3) = 9
From this, we get that:
Solving a quadratic equation:
Given a second order polynomial expressed by the following equation:
.
This polynomial has roots 
such that 
, given by the following formulas:
In this question:
Thus a quadratic equation with 
Then
Width is a positive measure, thus, the width of the cardboard is of 1.5 feet.
Another similar problem can be found at brainly.com/question/16995958
Answer:
It takes 50 minutes to paint the whole box
Step-by-step explanation:
1. Write an equation using equal fractions to represent this situation. Use a box to represent the total time it takes to paint the bookcase.
Wilson paints 40% of a bookcase in 20 minutes.
For the total box
40% = 20 minutes
100% = x
40 × x = 100 × 20
x = 100 × 20/40
x = 50 minutes
Answer:♀️
Step-by-step explanation:
