Answer:
8x+10
Step-by-step explanation:
2(x+5)+6x
Distribute
2x+10 +6x
Combine like terms
8x+10
Answer:
length of each edge = (x + 3)
Step-by-step explanation:
The surface area of each face of the cube = (
+ 6x + 9) 
. But the surface of a cube has the shape of a square. So that,
Area of a square = length x length
= 
By factorizing the area,
+ 6x + 9 = + 3x + 3x + 9
= ( + 3x) (3x + 9)
= x(x +3) + 3(x + 3)
= (x + 3)(x + 3)
= 
+ 6x + 9 =
Thus,
=
find the square root of both sides
l = (x + 3)
length of each edge = (x + 3)
Answer:
Yes, there is sufficient evidence to conclude that performance on the problem solving task is lowered by having onlookers.
Step-by-step explanation:
Null hypothesis: The performance on the problem solving task is lowered by having onlookers.
Alternate hypothesis: The performance on the problem solving task is not lowered by having onlookers.
Test statistic (t) = (sample mean - population mean) ÷ (sample sd/√n)
sample mean = 89.8
population mean = 89.1
sample sd = √sample variance = √84.6 = 9.198
n = 21
Degree of freedom = n-1 = 21-1 = 20
Assuming a 5% significance level
The test is a two-tailed test. Critical values corresponding to 20 degrees of freedom and 5% significance level are -2.086 and 2.086
Test statistic (t) = (89.8 - 89.1) ÷ (9.198/√21) = 0.7 ÷ 2.007 = 0.349
Conclusion:
Fail to reject the null hypothesis because the test statistic 0.349 falls within the region bounded by the critical values.
There is sufficient evidence to conclude that performance on the problem solving task is lowered by having onlookers.
