I believe its additive Inverse Property
We have been given that a colleague has been tutoring six students in 11th grade to prepare for the ACT. Student scores were as follows: 20, 18, 16, 15, 23, 20. We are asked to find the mean of the ACT scores.
We will use mean formula to solve our given problem.




Upon rounding to nearest whole number, we will get:

Therefore, the mean of the ACT scores is 19 and option 'c' is the correct choice.
Answer:
The solution to this question is 39
Step-by-step explanation:
Given that :
√(3x+7)+2√(x-8)=0.
√(3x+7)=-2√(x-8) (i)
square of the equation (i)
Then
(√(3x+7))^2=(-2√(x-8))^2
we know that √a*√a=(√a)^2=a So,
(3x+7)=4(x-8)
3x+7=4x-32 //multiply by 4
32+7=4x-3x exchange the value.
39=1x
x=39.
Answer:
Work out the number of boys and girls in each class below.
In class 8T, there are 9 boys.
The ratio of boys to girls is 1:2
Number of boys Number of girls = it's 0
X = 9
you multiply both sides by 3 because you have to get rid of it and what you do to one side you do to the other then you divide both sides by 2 to isolate the variable. i hope that makes sense.