I:2x – y + z = 7
II:x + 2y – 5z = -1
III:x – y = 6
you can first use III and substitute x or y to eliminate it in I and II (in this case x):
III: x=6+y
-> substitute x in I and II:
I': 2*(6+y)-y+z=7
12+2y-y+z=7
y+z=-5
II':(6+y)+2y-5z=-1
3y+6-5z=-1
3y-5z=-7
then you can subtract II' from 3*I' to eliminate y:
3*I'=3y+3z=-15
3*I'-II':
3y+3z-(3y-5z)=-15-(-7)
8z=-8
z=-1
insert z in II' to calculate y:
3y-5z=-7
3y+5=-7
3y=-12
y=-4
insert y into III to calculate x:
x-(-4)=6
x+4=6
x=2
so the solution is
x=2
y=-4
z=-1
Have u tryed 1 insted of -1 or it might be o solution
The general equation for computing the circumference of a circle is

, where C is the circumference, and d is the diameter. (You might also see the equation as

where r is the radius, because

)
Computing the circumferences of the two circles, we get:


.
To calculate the ratio of two numbers, we can divide one by the other. You can look at this as "How many times does the denominator fit in the numerator?"

So the circumference of the complex impact crater is 2 times greater than the circumference of the simple impact crater.
Answer:
x = 0
Step-by-step explanation:
Step 1: Write equation
-19 = x - 19
Step 2: Solve for <em>x</em>
- Add 19 to both sides: 0 = x
- Rewrite: x = 0
Step 3: Check
<em>Plug in x to verify it's a solution.</em>
-19 = 0 - 19
-19 = -19