Answer:
10 nickels and 10 quarters
Step-by-step explanation:
Given
Number of coins: 20
Vaiue of coins = $3.00
Required
Number of Nickels and Quarters;
<em>Let N =Nickels and Q =Quarters</em>
The total coins is represented as:

1 nickel is equivalent to $0.05 and 1 quarter is equivalent to $0.25; So

Make N the subject of formula in the first equation

Substitute this in the second equation


Collect like terms


Multiply both sides by 5


Recall that N = 20 - Q


440 gallons of 80 % antifreeze solution must be mixed with 80 gallons of 15% antifreeze to get a mixture that is 70% antifreeze
<em><u>Solution:</u></em>
Let "x" be the gallons of 80 % antifreeze added
Therefore, "x" gallons of 80 % antifreeze solution must be mixed with 80 gallons of 15% antifreeze
Final mixture is x + 80
Therefore, we can frame a equation as:
"x" gallons of 80 % antifreeze solution must be mixed with 80 gallons of 15% antifreeze to get (x + 80) gallons of 70 % antifreeze
Thus, we get,
x gallons of 80 % + 80 gallons of 15 % = (x + 80) gallons of 70 %

Thus 440 gallons of 80 % antifreeze solution must be mixed
Answer:

Step-by-step explanation:
Pay attention to the two tick marks. This indicates that those sides are congruent to each other and so will the angles on the bottom and top. Therefore, we can set up the equation
and solve for x:






Answer:
a) 1/800 or 0.00125
b) i) 0.0013
ii) 0.001
c) 60%
Step-by-step explanation:
T = [tan(2×30)+1][2cos(30)-1] ÷ (y²-x²)
T = (tan60 + 1)(2cos30 - 1) ÷ (41² - 9²)
T = (sqrt(3) + 1)(sqrt(3) - 1) ÷ 1600
T = (3-1)/1600
T = 2/1600
T = 1/800
T = 0.00125
Error: 0.002 - 0.00125
0.00075
%error
0.00075/0.00125 × 100
60%