The sub dives 37 feet....thats -37...it rises 16 ft....-37 + 16 = -21...then dives 18 ft.....-21 - 18 = - 39 ft
so the net change is -39 ft
A+5 = 1 side, so the perimeter is 3(a+5) or P = 3a+15
Answer:

Step-by-step explanation:
Answer:
The number of nickels is 45 and the number of dimes is 72.
Step-by-step explanation:
Let
x ----> number of nickels
y ----> number of dimes
Remember that


so
------> equation A

------> equation B
<em>Solve the system by substitution</em>
we have
------> equation A
------> equation B
Multiply both equations by 100 both sides
---->
--> equation C
----> equation D
substitute equation C in equation D

solve for y




Find the value of x




<em>Alternative Method</em>
Solve the system by graphing
Remember that the solution is the intersection point both graphs
using a graphing tool
the solution is the point (45,72)
therefore
The number of nickels is 45 and the number of dimes is 72.
3x^4 becomes 3(3x)^4=3*3^4*x^4
y^2 becomes (3y)^2=3^2y²
the new z=3² the old z, so b is correct.