we know that
If a ordered pair (x,y) is a solution of the equation, then the ordered pair must satisfy the equation
we have the equation
![7x-5y=28](https://tex.z-dn.net/?f=7x-5y%3D28)
Let's verify all the cases to determine the solution to the problem.
<u>case A)</u> point ![(-6,-14)](https://tex.z-dn.net/?f=%28-6%2C-14%29)
Substitute the values of x and y in the equation
![x=-6\\y=-14](https://tex.z-dn.net/?f=x%3D-6%5C%5Cy%3D-14)
![7(-6)-5(-14)=28](https://tex.z-dn.net/?f=7%28-6%29-5%28-14%29%3D28)
![-42+70=28](https://tex.z-dn.net/?f=-42%2B70%3D28)
-------> is true
therefore
The point
is a solution of the equation
<u>case B)</u> point ![(-1,-7)](https://tex.z-dn.net/?f=%28-1%2C-7%29)
Substitute the values of x and y in the equation
![x=-1\\y=-7](https://tex.z-dn.net/?f=x%3D-1%5C%5Cy%3D-7)
![7(-1)-5(-7)=28](https://tex.z-dn.net/?f=7%28-1%29-5%28-7%29%3D28)
![-7+35=28](https://tex.z-dn.net/?f=-7%2B35%3D28)
-------> is true
therefore
The point
is a solution of the equation
<u>case C)</u> point ![(4,10)](https://tex.z-dn.net/?f=%284%2C10%29)
Substitute the values of x and y in the equation
![x=4\\y=10](https://tex.z-dn.net/?f=x%3D4%5C%5Cy%3D10)
![7(4)-5(10)=28](https://tex.z-dn.net/?f=7%284%29-5%2810%29%3D28)
![28-50=28](https://tex.z-dn.net/?f=28-50%3D28)
-------> is not true
therefore
The point
is not a solution of the equation
<u>case D)</u> point ![(7,9)](https://tex.z-dn.net/?f=%287%2C9%29)
Substitute the values of x and y in the equation
![x=7\\y=9](https://tex.z-dn.net/?f=x%3D7%5C%5Cy%3D9)
![7(7)-5(9)=28](https://tex.z-dn.net/?f=7%287%29-5%289%29%3D28)
![49-45=28](https://tex.z-dn.net/?f=49-45%3D28)
-------> is not true
therefore
The point
is not a solution of the equation
therefore
<u>the answer is </u>
![(-6,-14)](https://tex.z-dn.net/?f=%28-6%2C-14%29)
![(-1,-7)](https://tex.z-dn.net/?f=%28-1%2C-7%29)
Answer:
8 π .
Step-by-step explanation:
radius increases at a constant rate of 1 in/sec.
dr / dt = 1
where r is radius .
radius after 4 sec
r = 1 x 4 = 4 in
area A = π r²
differentiating both sides
dA / dt = 2 π r dr / dt
Putting dr / dt = 1 , r = 4 in
dA / dt = 2 π x 4 x 1
= 8 π sq in per sec.
Area increases at the rate of 8 π per sec.
Answer:
y=-9x-4
Step-by-step explanation:
Perpendicular lines meet the following condition:
m2*m1= -1 (a)
where m is the slope of a line
m1 is given through equation of line 1, y =1/9 x+2
m2 must be -9 -> from eq. (a)
The Line has the following equation: y=mx+b, where m=-9 and the b is the interception with y axis.
Evaluating the above equation in (-1,5) we have the following equation
5= -9*(-1)+b, we have b=-4
The line has the following equation
y=-9x-4
Slope intercept form
Answer:
C : 20
good luck, hope this helped!