Answer:
Adding 5 from both sides then dividing by 7
Step-by-step explanation:
The best way to isolate x is to add 5 to both sides first:
21 = 7x
Then to isolate x by itself divide both sides by 7
x = 3
That would be the value of x and your final answer.
Find the mean of the first four test scores first.
(Add all numbers in set and divide by how many numbers there are)
81 + 87 + 71 + 89 = 328 / 4 = 82
Then, find the mean with the 85 added as the fifth term.
81 + 87 + 71 + 89 + 85 = 413 / 5 = 82.6
The impact that the 85 had on the mean test score was that the mean/average increased by 0.6.
The slope, or gradient, of the line is 6/-3 which is -2. The gradient is -2.
The answer should be x = 6
