Answer:
-55
Step-by-step explanation:
(6y - 11)(6y + 11) = ay
² - b |use (a - b)(a + b) = a² - b²
(6y)² - 11² =ay² - b
36y² - 121 = ay² - b |add b to both sides
ay² = 36y² - 121 + b |divide both sides by y² ≠ 0
a = (36y² - 121 + b)/y²
Answer:
After ten years his salary is x2
Step-by-step explanation:
Let x be the number.
"twelve decreased by twice a number" ---> 12 - 2x
"8 times the sum of number and 4" ---> 8(x + 4)
12 - 2x = 8(x + 4)
12 - 2x = 8x + 32 (distributive property)
12 = 10x + 32 (add 2x to both sides)
-20 = 10x (subtract 32 from both sides)
x = -2 (divide both sides by 10)
Answer:
The null hypothesis is: 
The alternative hypothesis is: 
Step-by-step explanation:
At the null hypothesis, we test if the mean is equal to a certain value.
At the alternate hypothesis, we test if the mean is less than, more than, or different from the value tested at the null hypothesis.
The tuft bind strength of a synthetic material used to make carpets is known to have a mean of 100 lb and standard deviation of 20 lb.
This means that the null hypothesis is: 
Could it be that the average tuft strength is above 100 lb?
The world above means that the appropriate alternative hypothesis is: 