Step-by-step explanation:

To solve, we will follow the steps below:
3x+y=11 --------------------------(1)
5x-y=21 ------------------------------(2)
since y have the same coefficient, we can eliminate it directly by adding equation (1) and (2)
adding equation (1) and (2) will result;
8x =32
divide both-side of the equation by 8
x = 4
We move on to eliminate x and then solve for y
To eliminate x, we have to make sure the coefficient of the two equations are the same.
We can achieve this by multiplying through equation (1) by 5 and equation (2) by 3
The result will be;
15x + 5y = 55 ----------------------------(3)
15x - 3y =63 --------------------------------(4)
subtract equation (4) from equation(3)
8y = -8
divide both-side of the equation by 8
y = -1
Step-by-step explanation:
B. 426 people per square. mile
Answer:
C
Step-by-step explanation:
You have to divide both sides by the coefficient of x
Answer:
x>-8
Step-by-step explanation:
7x+11>5x-5
2x+11>-5
2x>-16
x>-8
the > sign acts like an equal sign :)