Answer:
100㏑²
Step-by-step explanation;
first of all you find the base using the pythagoras theorem
that is, √13² - 12² =√25 = 5
so 5 is the base of the right angle in the big isoceles triangle
so the base of the isoceles triangle is 10 [5 + 5]
so for the first triangle the area is 60㏑²
the second triangle is 40㏑²
therefore 60 + 40 = 100㏑²
You have two unknown rates, so we need to develop two equations to solve for these unknowns (based on the information given on the problem statement):
5x + 10y = 725
x + y = 100
By substitution, we get:
5x + 10(100 - x) = 725
5x + 1000 - 10x = 725
-5x = 725 - 1000
-5x = -275
x = -275/-5 = 55
100 - 55 = 45
Thus:
The mechanic who worked for 5 hours charged his time at $55/hr, and the mechanic who worked for 10 hours charged his time at $45/hr.
To verify, plug and chug the results back into the original equations:
5(55) + 10(45) = 725
275 + 450 = 725
725 = 725 [OK]
55 + 45 = 100 [OK]
Answer:

Step-by-step explanation:
y-intercept is when x = 0, so (0, 2)
x-intercept is when y = 0, so (4, 0)

Slope-intercept form of linear equation: 
(where m is the slope and b is the y-intercept)
Given:

- b = 2

< ABC is a straight angle
no right angles
no complimentary angles
< ABD and < DBC are supplementary angles