00:01
We have to solve the system of two equations by the substitution method and then check the solution graphically.
00:08
So let's express y is a function of x from the first equation.
00:14
So y equals to negative x squared and now let's substitute y in the second equation.
00:20
So x squared minus 4x plus x squared equals to 0.
00:26
Therefore this equation can be simplified, so 2x.
00:31
X minus multiplied by x minus 2 equals to 0 so therefore there are two solutions x equals to 0 and x equals to 2 so means that the system has two solutions so the first solution is 0 0 and the second solution is 2 minus 4 now let's check it graphically so the first equation is a parabolic function so is the second one but let's consider the second one more deeply.
01:11
X squared minus 4 x equals to y.
01:17
So the coefficient before x squared is positive, therefore the function has a minimum.
01:26
So an x minimum equals to minus 4 divided by 2, which is 2.
01:33
So y minimum value of the function equals to negative 4...