W= width
L= length= 2W-4
Perimeter= 70
FIND WIDTH:
P= 2(L + W)
P= 2L + 2W
substitute 2W-4 for L
70= 2(2W-4) + 2W
multiply 2 by all in parentheses
70= (2*2W) + (2*-4) + 2W
70= 4W - 8 + 2W
combine like terms
70= 6W - 8
add 8 to both sides
78= 6W
divide both sides by 6
13= W
FIND LENGTH:
substitute w=13 to find width
L= 2W-4
L= 2(13)-4
L= 26-4
L= 22
CHECK:
P= 2(L + W)
70= 2(22 + 13)
70= (2*22) + 2(13)
70= 44 + 26
70= 70
ANSWER:
length= 22 inches
width= 13 inches
Hope this helps! :)
Answer:
no solution ...................
Let n = number of nickels, and p = number of pennies.
The number of coins is 25, so we get this equation.
n + p = 25
The value of the coins is 0.05 per nickel, and 0.01 per penny.
0.05n + 0.01p = 0.73
Now you have a system of equations.
n + p = 25
0.05n + 0.01p = 0.73
Solve the first equation for n:
n = 25 - p
Now substitute into the second equation.
0.05(25 - p) + 0.01p = 0.73
1.25 - 0.05p + 0.01p = 0.73
-0.04p = -0.52
p = 13
There were 13 pennies.
Now we substitute 13 for p in n + p = 25 to find out the number of nickels.
n + 13 = 25
n = 12
There are 13 pennies and 12 nickels.
Check: 13 pennies and 12 nickels does total 25 coins.
13 * 0.01 + 12 * 0.05 = 0.13 + 0.60 = 0.73
The value is $0.73.
Our answer is correct.
Answer:
144
Step-by-step explanation:
