for these you need to rearrange the equations and do substitutions.
#3 = if x+y=5 then you know x = 5-y
now substitute that equation for x in the 2nd one so x + 2y = 8 becomes
5-y + 2y = 8 2y - y becomes 1y which becomes y then subtract 5 from each side to get y =3
now replace y with 3 in the first equation x = 5-3 so x = 2
so (2,3) is the answer
same type of work for #4
2x-y=6 ,S0 y = 2X+6
so now you have 4x+2(2x+6)=-4
that becomes 4x +4x+12 = -4
8x+8 = 1, x =1
y = 2(1)-6 = -4
so answer is (1,-4)
The answer for your question is x=-1
Answer:

Step-by-step explanation:
Circumference is the perimeter of a circle. It can be found using the formula:

However, we are given the radius.
- The radius measures from the center to the edge of the circle.
- The diameter measures from edge to edge through the center.
- So, the diameter is twice the radius, or d=2r
The formula can be rewritten as:

We know the circumference is 25.12 inches.

Let's round pi to 3.14

We want to solve for the radius, so we must isolate it.
Divide both sides by 3.14 because the inverse of multiplication is division.


Divide both sides by 2.


The radius of the disc is <u>4 inches.</u>
Answer:
is the answer your looking for
Step-by-step explanation:
-2x -9y = -25
-(-4x -9y =-23)
2x = -2
x = -1
-2(-1) -9y = -25
2 - 9y = -25
-9y = -25 -2
-9y = -27
y = 3
(-1,3)