Answer:
37 dimes and 10 nickels
Step-by-step explanation:
let d = # dimes
let n = # nickels
we can set up a system of equations:
n + d = 47
.05n + .10d = 4.2
if we solve the first equation for 'n' we get:  
n = 47-d
now we can substitute this in for 'n' in the second equation:
.05(47-d) + .10d = 4.2
2.35 - .05d + .10d = 4.2
2.35 + .05d = 4.2
subtract 2.35 from each side to get:
.05d = 1.85
d = 1.85÷.05
d = 37
if d+n = 47 and d=37 then n = 10
Check:
.05(10) + .1(37) should equal 4.2
.50 + 3.7 = 4.2  [It Checks Out]
 
        
             
        
        
        
Answer:
3x+6.9 and 3x-4
Step-by-step explanation:
since 3 x x is 3x and the sign in the bracket is addition you place it there then place 3 x 2.3 
being 6.9.
1/3 x 9is 9/3 and 3 can multiply both sides to get 3/1 or 3 then bring the minus and 1/3 x 12 is 12/3 3 can multiply both sides to get 4/1 or 4
 
        
             
        
        
        
Answer:
This is not a question.
Step-by-step explanation:
 
        
             
        
        
        
Answer:
Tanong mo sa teacher mo ha ha ha ha 
 
        
             
        
        
        
Answer:
False
Step-by-step explanation:
We need both points, because one is the y, adn it is what the equation equals to, and the x is the thing that comes after the slope. 
Example:
m=2
(3,0)
y=mx+b
0=(2)(3)+b
0=6+b
0-6=b
-6=b