9514 1404 393
Answer:
x = 7
Step-by-step explanation:
You solve a linear equation by putting the variable on one side of the equal sign and a constant on the other side. Here, variables and constants are on both sides of the equal sign, so you need to separate them.
The basic idea is that you add the opposite of any term you don't want. Whenever you perform any operation (like "add"), <em>you must do it to both sides of the equation</em>.
We observe that x-terms have coefficients of 10 and 9. We choose to add the opposite of 9x to both sides:
10 -9x -5 = 9x -9x +2
x -5 = 2 . . . . simplify
Now, we still have -5 on the left, where we don't want it. So, we add its opposite (+5) to both sides:
x -5 +5 = 2 +5
x = 7 . . . . simplify
The solution is x = 7.
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<em>Additional comment</em>
If we were to end up with an x-coefficient other than 1, we would divide both sides of the equation by that coefficient. This will leave the x-term with a coefficient of 1.
To solve problems like this you can either graph or solve mathematically. To do the ladder we need to solve for one variable at a time. So lets cancel one variable out.
Multiply equation 1 by 2
This will give 4x-2y=14
Now we can get rid of y by subtracting 2 from 1
This will give x=9
Plug back in to either equation, i will use equation 2
3(9)-2y=5 simplify
-2y=-22 solve
Y=11
Answer:
10 miles
Step-by-step explanation:
The center is at origin O(0,0).
If it contains the point, P(-8,6), then the radius r is, by Pythagoras theorem,
r=sqrt((-8)^2+6^2)=10
The general equation of a circle at centre (xc,yc) with radius r is given by
(x-xc)^2+(y-yc)^2=r^2
Substituting r=10, (xc,yc)=(0,0)
the resulting equation is therefore
(x-0)^2+(y-0)^2=10^2
or simply
x^2+y^2=100
