Answer:
40/9
Step-by-step explanation:
Use the work formula, 
+ 
= 
, where A is the amount of time it takes one person, B is the amount of time it takes another person, and T is the time it takes for them to work together.
Plug in the times for David and Alex alone:
+ 
=
Find the least common denominator, which is 40.
+ 
=
=
Cross multiply and solve for T:
9T = 40
T = 40/9
So, if they worked together, it would take them 40/9 hours
Answer:
c. first quadrant
Step-by-step explanation:
First Quadrant : 0° to 90°
Second Quadrant : 90° to 180°
Third Quadrant : 180° to 270°
Fourth Quadrant : 270° to 360° (or 0°)
The formula to use here would be:
A = P(1+r)^t where P is the principal (starting) amount, r is the rate of interest, and t is time. Knowing this, plug in your values:
A = 14,000(1+0.07)^4 once worked out, you should get $18,351.14414 < this is the total amount he would be paying at the end of 4 years. to find the interest, subtract this amount from the principal amount (14,000):
$18,5351.14414 - 14,000 = 4,351.14414 < this is the amount of interest. Round your answer.
Answer: Jamal will pain $4,351.14 interest.
