Answer:
(1.5,-2.6)
Step-by-step explanation:
Given the polar coordinates (-3,60°).
Let our Cartesian coordinates be (x,y)
#We know that when converting the rectangular coordinates (x,y) to polar (r,θ), then:

#Using the illustration above, we can express our polar coordinates as:

#Solve simultaneously to solve for x and y:

Hence, the Cartesian coordinates are (1.5,-2.6)
A * b = 30
a - b = 1
a + b = 11
take ur last 2 equations, and add them
a - b = 1
a + b = 11
--------------add
2a = 12
a = 12/2
a = 6
now its just a matter of subbing
a + b = 11
6 + b = 11
b = 11 - 6
b = 5
so a = 6 and b = 5...whose product is 30, whose difference is 1, and whose sum is 11.
The answer would be C. We know that d is equal to the initial depth of a lake. The two given initial depths are 58 feet and 53 feet, so we know that one of the equations must be either d=58 or d=53. Because there only C has either one of those, d=58, we know that it must be the answer.
To find the other equation, it is just a linear function for the other lake. The y-intercept, or initial value, is 53, so in the equation y=mx+b, it is the b value. The slope, or m value, is 3 feet, so you have y=d=3x+53.
Answer:
D 15
Step-by-step explanation:
5x when x=3
=5×3
=15