Answer:
a=2.48
c=9.52
Step-by-step explanation:
a+c=12
4a+7.5c=72.5 Given
a+c=12
-4a-7.5c=-72.5 multiply the equation by negative 1
-3a-6.5c=-60.5 simplify
-3a=-60.5+6.5c add 6.5c to both sides
a=-20.17+2.17c divide it by 3
now you would take that equation and plug it into an equation you already have since you have something to plug in for a, the easiest one to do is a+c=12
(-20.17+2.17c)+c=12 plug in the equation
-20.17+3.17c=12 simplify by solving for c
3.17c=30.17 add 20.17 to both sides
c=9.52 divide both sides by 3.17
now since you have found c, you can plug it in to you equation to solve for a now (use the ones from the second step). I am using the equation a+c=12.
a+9.52=12 plug in the variable and solve for a
a=2.48 subtract 9.52 to both sides
a=2.48
c=9.52
Expand the right side:


Notice that 98 = 2 * 7 * 7, so we have
and
.
Then

and

Considering the given angle and the given formula, it is found that the percentage error for an angle of 0.02 radians is of 0.0067%.
<h3>What is the percentage angle for an angle?</h3>
For an angle
, it is given by the following formula:

In this problem, the angle is of
, hence:


The percentage error for an angle of 0.02 radians is of 0.0067%.
More can be learned about percent error at brainly.com/question/25224978
Answer:
d. 40 units
Step-by-step explanation:
The length of the horizontal side of this rectangle on the line y=20 is the difference of the x-coordinates, 12 and 20, so is 8. The length of the vertical side on the line x=20 is the difference of the y-coordinates, 20 and 8, so is 12.
Two sides are of length 8 and two are of length 12. The perimeter is the sum of the side lengths, so is ...
P = 2·8 +2·12 = 40 . . . units