Answer:
Beginner. Use a paper strip coated in a pH indicating dye. Dip the strip into the water and wait for the strip to change color. ...
Intermediate. Use a pH testing kit for liquids. ...
Advanced. A digital pH meter can be used to obtain the most accurate reading of the pH level.
Step-by-step explanation:
Let's say a = number of ordered soups, b = number of ordered sandwiches.
Then 4.5a + 7.75b = 113.50, and a and b are integers between 0 and 18 inclusive.
How do we tackle this? If all ordered soup, the cost would be $81, so we'll have at least 4 sandwiches. If all ordered sandwich, the cost would be $139.5, so at most 15 sandwiches were ordered. You also know an even number of sandwiches was ordered, to let the price end at 50 cent.
If you brute-force from 4,6,8,10,12 to 14 sandwiches, you find the answer at 10 sandwiches and 8 soups.
10*7.75 + 8*4.50 = 113.50
Answer:
x = -4
Step-by-step explanation:
Solve for x:
3 x - 5 x + 2 = 10
Grouping like terms, 3 x - 5 x + 2 = 2 + (3 x - 5 x):
2 + (3 x - 5 x) = 10
3 x - 5 x = -2 x:
-2 x + 2 = 10
Subtract 2 from both sides:
(2 - 2) - 2 x = 10 - 2
2 - 2 = 0:
-2 x = 10 - 2
10 - 2 = 8:
-2 x = 8
Divide both sides of -2 x = 8 by -2:
(-2 x)/(-2) = 8/(-2)
(-2)/(-2) = 1:
x = 8/(-2)
The gcd of 8 and -2 is 2, so 8/(-2) = (2×4)/(2 (-1)) = 2/2×4/(-1) = 4/(-1):
x = 4/(-1)
Multiply numerator and denominator of 4/(-1) by -1:
Answer: x = -4
The lines mean that they are parallel
(553-265)/48=6
6 hours spent repairing the car
