There is actually 2 ways to solve this, I will show you both.
The first is obvious, solve for x in the first one, and plug it into the 2nd one and get the answer
4x + 7 = 12
4x = 5
x = 
8( ) + 3
) + 3
2 * 5 + 3
10 + 3
13
The 2nd option is to manipulate the 4x + 7 to be 8x + 3
4x + 7 = 12
start by moving the 7 over
4x = 5
multiply both sides by 2
8x = 10
and add 3 to both sides
8x + 3 = 13
 
        
                    
             
        
        
        
Answer:
 1 11/21
Step-by-step explanation:
6/7 + 2/3 = 32/21 
32/21 simplified is 1 11/21
 
        
             
        
        
        
Line:
3x+y=7
y=-3x+7
Slope of Perpendicular Line: 1/3x
For the perpendicular line to contain point (6,-1) the y-intercept would be (0,1), thus the equation of the line would be y=1/3x+1
y=1/3x+1
        
             
        
        
        
<span>I = Prt, where P is the principal, r is the annual </span>interest<span> rate in decimal form, and t is the loan period expressed in years.
</span>
First, Let us convert 3.4% into decimal form. <span>Move the decimal point two places to the left, adding in zeros as needed. 0.034</span>
Second, lets plug in our information. 
250 * 0.034 * 3 = 25.50 
Your simple interest is: $25.50
        
             
        
        
        
Answer:

Step-by-step explanation:
So we have: 

Distribute: 

Combine like terms: 

Subtract 12x from both sides: 

Add 30 to both sides: 

Divide both sides by -16: 

And that's our answer :)