5x+7y=25
5x-2y=-65
subtract both of the equations
5x-5x=0
7y--2y= 7y+2y=9y
25--65=25+65=90
0+9y=90
9y=90
divide both sides by 9 to get y by itself
9y/9=90/9
cross out 9 and 9 which becomes 1*1*y=y
90/9=10
y=10
find x by using the substitution method
5x+7y=25
5x+7(10)=25
5x+70=25
move +70 to the other side
sign changes from +70 to -70
5x+70-70=25-70
5x=-45
divide both sides by 5 to get x by itself
5x/5=-45/5
cross out 5 and 5 then becomes 1*1*x=x
-45/5=-9
x=-9
answer:
(-9,10)
Answer: 7/13 is already in simplest form.
Step-by-step explanation:
The sides cannot both be divided by the same number, meaning it is already in simplest form.
The correct answer to the first question is: A'(-5, 6)
The second answer is un-answerable, because the pictures you have provided do not display triangles.
Answer:

Step-by-step explanation:
1st boat:
Parabola equation:

The x-coordinate of the vertex:

Equation:

The y-coordinate of the vertex:

Parabola passes through the point (-8,1), so

Solve:

Parabola equation:

2nd boat:
Parabola equation:

The x-coordinate of the vertex:

Equation:

The y-coordinate of the vertex:

Parabola passes through the point (-8,1), so

Solve:

Parabola equation:

System of two equations:

Start at 5 and go up 3 and move 4 to the right