Answer:
15.8 cm²
Step-by-step explanation:
Please see attached photo for diagram. 
We'll begin by calculating the angle A. This can be obtained as follow:
B = 56°
C = 78°
A =? 
A + B + C = 180 (Sum of the angle in triangle)
A + 56 + 78 = 180
A + 134 = 180
Collect like terms
A = 180 – 134
A = 46°
Next, we shall determine the value of b by using the sine rule. This can be obtained:
Side opposite angle C (c) = 7.2 cm
Angle C = 78°
Angle B = 56°
Side opposite angle B (b) =? 
b/Sine B = c/sine C
b/Sine 56 = 7.2/Sine 78
Cross multiply 
b × Sine 78 = 7.2 × Sine 56
Divide both side by Sine 78
b = 7.2 × Sine 56 / Sine 78
b = 6.1 cm
Finally, we shall determine the area of the triangle. This can be obtained as follow:
Side opposite angle C (c) = 7.2 cm
Side opposite angle B (b) = 6.1 cm
Angle A = 46°
Area (A) =? 
A = ½bcSineA
A = ½ × 6.1 × 7.2 × Sine 46
A = 15.8 cm²
Therefore, the area of the triangle is 15.8 cm²
 
        
             
        
        
        
E^3t=100
ln100=3t
t=(ln100)/3
        
             
        
        
        
A=a+b+c+d/4
subtract a from both sides
0=b+c+d/4
Subtract b from both sides
-b=c+d/4
Finally subtract d/4 from both sides
c=-d/4-b
        
             
        
        
        
9.35
= 9.00 + 0.35
= 9 + 7/20
= 180/20 + 7/20
= 187/20
        
                    
             
        
        
        
Answer:
See explanation below
Step-by-step explanation:
The best explanation is noticing that in order to get from the point R (12, 1) to the point Q (7, 4) we move 5 units to the left and 3 units up. And to go from point Q (7, 4) to point P (2, 7) we do exactly the same: move 5 units to the left and 3 units up. That means that these points are all connected via the same rate of change:  - 3/5, which is in fact the slope of the line the three points belong to.