This is how I would solve it:
1st # = x                 4(x+1)=3x+18
2nd # = x+1              4x+4=3x+18
                                     4x=3x+14
                                       x=14
To check: 15x4=60; 60-42=18.       <u>1st # = 14; 2nd # = 15.</u>
        
             
        
        
        
11g greater than 5
Step-by-step explanation:
 
        
                    
             
        
        
        
Use this systems of equations to solve:
x = first antifreeze
y = second antifreeze

Isolate y.
x + y = 15
Subtract x from both sides.
y = -x + 15
Substitute y into the other equation.
.2x + .12(-x + 15) = .18(15)
Simplify.
.2x - .12x + 1.8 = 2.7
Subtract 1.8 from both sides.
.08x = .9
Divide both sides by .08
x = 11.25
Substitute x in the equation that we isolated y in.
y = -11.25 + 15
y = 3.75
11.25 L of the first antifreeze and 3.75 L of the second.
 
        
        
        
Answer:
Third graph in the photo
Step-by-step explanation:
x^2+3x-4 can be factored as (x+4)(x-1). When y=0, x must be -4 or 1 to satisfy the equations, and thus the roots of the graph are at x=-4 and x=1. When x=0, y=(4)(-1)=-4. The only graph that satisfies both of these requirements is the third/last one.
 
        
             
        
        
        
10% off 
= $4.80
30% off 
= $4.80 x 3
= $14.40
$48 + $14.40
= $62.40
The original price was $62.40