Answer:
(-8, -1)
Step-by-step explanation:
The problem tell us that y = -1. Plug in this y-value to wherever you see a y in the first equation. You should be able to solve from there. Your solution will be (-8,-1).
-2x - 3(-1) = 19
-2x + 3 = 19
-2x = 16
x = -8
For this particular problem, you could have also looked at the answer choices and seen that there was only one answer with the correct y-value.
4x + 5y = 5 / (-1)
8x + 5y = 25
-4x - 5y = -5
8x + 5y = 25
-4x + 8x = -5 + 25
4x = 20
x = 5
4x + 5y = 5
4*5 + 5y = 5
20 + 5y = 5
5y = 5 - 20
5y = -15
y = -3
8x + 5y = 25
8 *5 + 5y = 25
40 + 5y = 25
5y = 25 - 40
5y = -15
y = -3
Answer: 14:3
Step-by-step explanation:
Given
Ratio between students(s) to female(f) adults is 7:6
while ratio between female(f) to male(m) is 4:1
So, we can write
![\Rightarrow \dfrac{s}{f}=\dfrac{7}{6}\quad \ldots(i)](https://tex.z-dn.net/?f=%5CRightarrow%20%5Cdfrac%7Bs%7D%7Bf%7D%3D%5Cdfrac%7B7%7D%7B6%7D%5Cquad%20%5Cldots%28i%29)
Also, we can write
![\Rightarrow \dfrac{f}{m}=\dfrac{4}{1}\quad \ldots(ii)](https://tex.z-dn.net/?f=%5CRightarrow%20%5Cdfrac%7Bf%7D%7Bm%7D%3D%5Cdfrac%7B4%7D%7B1%7D%5Cquad%20%5Cldots%28ii%29)
Multiply both equations
![\Rightarrow \dfrac{s}{f}\times \dfrac{f}{m}=\dfrac{7}{6}\times \dfrac{4}{1}\\\\ \Rightarrow \dfrac{s}{m}=\dfrac{14}{3}](https://tex.z-dn.net/?f=%5CRightarrow%20%5Cdfrac%7Bs%7D%7Bf%7D%5Ctimes%20%5Cdfrac%7Bf%7D%7Bm%7D%3D%5Cdfrac%7B7%7D%7B6%7D%5Ctimes%20%5Cdfrac%7B4%7D%7B1%7D%5C%5C%5C%5C%20%5CRightarrow%20%5Cdfrac%7Bs%7D%7Bm%7D%3D%5Cdfrac%7B14%7D%7B3%7D)
So, the ratio of the students to male adults is 14:3 .
A and C are correct I believe