The average score of all the students in both classes is 84.
<h3>How to calculate the average?</h3>
The class with 30 students had an average score of 80 on a test. The total score will be:
= 30 × 80
= 2400
A class with 20 students had an average score of 90 on the same test. The total score will be:
= 20 × 90
= 1800
Total scores = 2400 + 1800 = 4200
Number of students = 20 + 30 = 50
The average score will be:
= Total score / Total students
= 4200 / 50
= 84
Learn more about average on:
brainly.com/question/24313700
#SPJ1
Answer:
D
Step-by-step explanation:
The equation of a circle centred at the origin is
x² + y² = r² ( where r is the radius )
Here r = 15, thus
x² + y² = 15² , that is
x² + y² = 225 → D
The result of the multiplication in scientific notation is given by:
<h3>What is scientific notation?</h3>
A number in scientific notation is given by:
With the base being 
.
When we multiply two numbers in scientific notation, we multiply the bases and add the exponents.
For this problem, the numbers are given by:
The result of the multiplication is given by:
The result of the multiplication in scientific notation is given by:
More can be learned about scientific notation at brainly.com/question/16394306
#SPJ1
Hello!
You can break this down
If she added 8 to the number
x + 8
Multiplied the sum by 2
2(x + 8)
it would equal 6
2(x + 8) = 6
The answer is B
Hope this helps!
F(-7)=0
Because that makes the (x+7) factor equal zero and any other factor multiplied by zero also results in zero.
