Answer:
x + y = 4 Equation 1
y = 2x -1 Equation 2
-2x + y = -1
 x + y = 4
Subtract 
You will get
- 3x = -5
Divide by -3
-3x / -3 = - 5 /-3
x = 5/3
Substitute x into equation 1
x + y = 4
x = 5/3
5/3 + y = 4
y = 4 - 5/3
y = 7/3
x = 5/3 y = 7/3
Hope this helps.
 
        
             
        
        
        
9514 1404 393
Answer:
   (6.2, 4.5)
Step-by-step explanation:
We want, for some point P, ...
   (P -A) / (B -P) = 1 / 3
   3(P -A) = (B - P) . . . . . multiply by 3
   4P = B +3A . . . . . . . . add P+3A
   P = (B +3A)/4 . . . . . . .divide by 4
Filling in the coordinate values, we can find P to be ...
   P = ((2.3, 5.4) +3(7.5, 4.2))/4 = (2.3+22.5, 5.4+12.6)/4
   P = (6.2, 4.5)
 
        
             
        
        
        
 The problem statement suggests you should convert dimensions to inches to work this problem.
.. 2.75 ft = 33 in
.. 1.5 ft = 18 in
The empty height is
.. 0.6*7 in = 4.2 in
so the empty volume is
.. V = (33 in)*(18 in)*(4.2 in) = 2494.8 in³
Multiplying this by the conversion factor to gallons gives
.. V = (2494.8 in)³ × (1 gal)/(231 in³) = 10.8 gal
It will take 10.8 gallons of gas to fill the tank.