Find the solution to the system of equations by using either graphing or substitution.
y+x=3
y-2x=18
(-4.5,7.5)
(-5,8)
(-6,9)
(-7.5,10.5)
can someone please explain I am so confused..
To find the solution to the system of equations using substitution, we can solve one equation for a variable and then substitute that expression into the other equation.
Let's solve the first equation, y + x = 3, for y:
y = 3 - x
Now we can substitute this expression for y in the second equation, y - 2x = 18:
(3 - x) - 2x = 18
Simplifying the equation:
3 - x - 2x = 18
3 - 3x = 18
-3x = 15
x = -5
Now we can substitute the value of x into one of the original equations to solve for y. Let's substitute -5 into the first equation y + x = 3:
y + (-5) = 3
y - 5 = 3
y = 8
So the solution to the system of equations is x = -5 and y = 8. This corresponds to the point (-5, 8).
Therefore, the correct answer is (-5, 8).
y+x=3
y-2x=18
subtract the bottom from the top and you have
3x = -15
x = -5
so, y = 8