Answer:
Step-by-step explanation:
What we have is a general equation that says this in words:
Laura's hours + Doug's hours = 250 total hours
Since we don't know either person's number of hours, AND since we can only have 1 unknown in a single equation, we need to write Laura's hours in terms of Doug's, or Doug's hours in terms of Laura's. We are told that Doug spent Laura's hours plus another 40 in the lab, so let's call Laura's hours "x". That makes Doug's hours "x + 40". Now we can write our general equation in terms of x:
x + x + 40 = 250 and
2x = 210 so
x = 105
Since Laura is x, she worked 105 hours in the lab and Doug worked 40 hours beyond what Laura worked. Doug worked 145. As long as those 2 numbers add up to 250, we did the job correctly. 105 + 145 = 250? I believe it does!!
Answer:
y = 9.84 mm
Step-by-step explanation:
<h2>Sine rule:</h2>
Law of sine:

a = y
A = 31°
b = 17 mm
B = 117°


Answer:
115.48
Step-by-step explanation:
This shape can be split into two distinct shapes
Two halves of a semi circle, and a rectangle in between
Circle:
Putting both halves of the semi circle together will give you a full circle. The diameter of the circle is given (7m).
The area of a circle is A = π 
The radius, r, is half of the diameter, so 7 / 2 = 3.5m
A = π 
A = π * 
A = 38.38
Rectangle:
The area of a rectangle is A = h b
The height, h, is known at 7m
The base, b, can be found by removing the length from the dot to the end of the semi circles. This length is the radius of the semi circles, 3.5m
Removing the radius from the total length given
18 - 3.5 - 3.5 = 11m
The base is 11m
A = h b
A = 7 * 11 = 77
Total Area = Circle area + Rectangle area
Total Area = 38.38 + 77 = 115.48
25+0.11n>12+0.36n
13>0.25n
n<52
Option b will cheaper then quantity of miles less than 52 miles.