Answer:
5 and 2
Step-by-step explanation:
-15 / -3 = 5
-20 / -4 = 5
6 / 3 = 2
10 / 5 = 2
Answer:
y = -0.5
Step-by-step explanation:
given
5x – 7y = 7 ------- eq 1
y = -5x + 3 (we rearrange this so that the terms are in the same order as eq 1)
-5x – y = -3 ----- eq 2
by elimination, eq 1 + eq 2
(5x – 7y) + (-5x – y) = 7 + (-3)
5x - 7y -5x - y = 7-3
-8y = 4
y = 4/(-8)
y = -0.5
Answer:
Problem 1: 
Problem 2: 
Problem 3: 
Step-by-step explanation:
Problem 1:
So we are going to use the following to help us:



So if we make those substitution into the first equation we get:



Factor the
out:

The following is a Pythagorean Identity:
.
We will apply this identity now:

This implies:

We don't need both because both of include points with radius 4.
Problem 2:



Factoring out
from first two terms:

Apply the Pythagorean Identity I mentioned above from problem 1:


or if we factor out r:


r=0 is actually included in the other equation since when theta=0, r=0.
Problem 3:


Answer:
25 boys.
Step-by-step explanation:
To solve this problem, first add the two parts of the ratio. 9 + 5 = 14. Then divide 70 by 14 to get 5. Since the total is 5 times the ratio total, multiply both sides of the ratio by 5. The result is 45 : 25. If you add them together, you get a total of 70. Therefore, there are 25 boys in the class.