Answer: If the 40% off coupon is used, the subtotal will be $12.69
The gratuity would be exactly $4.23 (He will probably leave $4.25)
Step-by-step explanation: To find out the amount of the discount
.40 × 21.15 = 8.46
To find the new subtotal, subtract 12.15 - 8.46 = 12.69
To figure the tip: .20 × 21.15 = 4.23
Changing the percent to a decimal means divide the 20 by 100.
Y=2x+6
gradient is found from the formula,

y intercept is found by subbing the values of (-1,4) into the equation y=2x+c
A(r)=3.14r^2, when r=5
A(5)=3.14(5^2)
A(5)=3.14(25)
A(5)=78.5 u^2
Answer:

Step-by-step explanation:
Given:
Sam takes x minutes yo walk from home to library.
And takes 5 minutes more to walk from the library to school than from home to the library.
Express the total time taken for Sam to walk from home to school via the library in terms of x.
<u>Solution:</u>
Time taken by Sam to walk from home to library = 
Time taken by Sam to walk from library to school = 
Total time taken by Sam to walk from home to school via the library = Time taken to walk from home to library + Time taken to walk from library to school
Total time taken = 
Therefore, the total time taken for Sam to walk from home to school via the library is 
C has a negative answer. hope this helps