Step-by-step explanation:
(3x+20)² is the same as
(3x+20)(3x+20)
you need to have for different numbers
SO
3x*3x is 9x²
3x*20 is 60x
20*3x is also 60x
20*20 is 400
put it together
9x²+60x+60x+400
simplify to
9x²+120x+400
Answer:
x = 102 , y = 35
Step-by-step explanation:
x and 78 are same- side interior angles and sum to 180° , that is
x + 78 = 180 ( subtract 78 from both sides )
x = 102
x and 6y - 108 are vertically opposite angles and are congruent , so
6y - 108 = 102 ( add 108 to both sides )
6y = 210 ( divide both sides by 6 )
y = 35
Answer:
8 < x < 34
Step-by-step explanation:
ab = 13, ac = 21, bc = x
The longest side of a triangle must be less than the sum of the other two sides.
If 21 is the longest side:
21 < 13 + x
8 < x
If x is the longest side:
x < 13 + 21
x < 34
Therefore, 8 < x < 34.
Increasing the sample size by a factor of 4 or multiplying
it by 4 is equal to increasing the standard error by 1/2. Therefore, the
interval will be half as varied. This also works almost for population
averages as lengthy as the multiplier from the t-curve doesn't modify much when
increasing the sample size.
