2l+2w=24
l=3+w
The first equation comes from the perimeter formula. Since it is a rectangle, there are two lengths and two widths, which must all be added to get the perimeter. The second equation shows that the length is equal to the width plus three. In order to solve this equation, the substitution method should be used, since the one equation is already set equal to one of the variables (L)
2l+2w=24
l=3+w
2(3+w)+2w=24
Use distributive property to get rid of the parentheses
2(3+w)+2w=24
2(3)+2(w)+2w=24
6+2w+2w=24
Simplify like terms on the left side of the equation
6+2w+2w=24
6+4w=24
Subtract six from each side so that all of the w's are on one side
6+4w-6=24-6
4w=18
Divide each side by four to find the value of one w
4w/4=18/4
w=4.5
Plug 4.5 into the one equation to find the value of l
l=3+4.5
l=7.5
Put the numbers into the first equation and simplify:
2(7.5)+2(4.5)=24
15+9=24
24=24
So the length would be 7.5 inches, and the width would be 4.5 inches
Answer:
The point estimate used was of $69,821.
The error bound is of $101.
Step-by-step explanation:
A confidence interval has two bounds, a lower bound and an upper bound.
A confidence interval is symmetric, which means that the point estimate used is the mid point between these two bounds, that is, the mean of the two bounds.
The error bound is half the difference between these two values.
In this question:
90% confidence that the mean household income in the U.S. falls between $69,720 and $69,922.
Point estimate:
(69720+69922)/2 = 69821
The point estimate used was of $69,821.
Error bound:
(69922 - 69720)/2 = 101
The error bound is of $101.
121 ways because 11*11=121 and 11 is the amount of photos you have
The answer is -12 hope this helps