Answer:
7(3a + 5)
Step-by-step explanation:
Rewrite 21 as 7 · 3
Rewrite 35 as 7 · 5
Therefore,
⇒ 21a + 35 = 7 · 3a + 7 · 5
Factor out common term 7:
⇒ 7 · 3a + 7 · 5 = 7(3a + 5)
Answer:
9x² − 12x + 4
Step-by-step explanation:
A perfect square trinomial:
a² + 2ab +b²= (a + b)²
a² - 2ab +b²= (a - b)²
9x² − 12x + 4 = (3x)² - 2*(3x)*2 + 2² = (3x - 2)²
36b² − 24b + 16
16x² − 24x − 9
4a² − 10a − 25
Answer:
The letter "x" is often used in algebra to mean a value that is not yet known. It is called a "variable" or sometimes an "unknown". In x + 2 = 7, x is a variable, but we can work out its value if we try! A variable doesn't have to be "x", it could be "y", "w" or any letter, name or symbol. See: Variable.
Step-by-step explanation:
Answer:
A. R2 = 0.6724, meaning 67.24% of the total variation in test scores can be explained by the least‑squares regression line.
Step-by-step explanation:
John is predicting test scores of students on the basis of their home work averages and he get the following regression equation
y=0.2 x +82.
Here, dependent variable y is the test scores and independent variable x is home averages because test scores are predicted on the basis of home work averages.
The coefficient of determination R² indicates the explained variability of dependent variable due to its linear relationship with independent variable.
We are given that correlation coefficient r= 0.82.
coefficient of determination R²=0.82²=0.6724 or 67.24%.
Thus, we can say that 67.24% of total variability in test scores is explained by its linear relationship with homework averages.
Also, we can say that, R2 = 0.6724, meaning 67.24% of the total variation in test scores can be explained by the least‑squares regression line.
