X + y= 4 xy = -45 решить систему уравнений

Предыдущий
вопрос Следующий
вопрос

To solve this system of equations, we can use the method of substitution.

First, we can rewrite the first equation as x = 4 - y.

Then, substitute this expression for x into the second equation:

(4 - y)y = -45
4y - y^2 = -45
Rearrange the equation:
y^2 - 4y - 45 = 0

Now, we can solve this quadratic equation for y by factoring or using the quadratic formula.

(y - 9)(y + 5) = 0
y = 9 or y = -5

Now that we have the values for y, we can substitute them back into the equation x = 4 - y to find the corresponding values for x.

For y = 9:
x = 4 - 9
x = -5

For y = -5:
x = 4 - (-5)
x = 4 + 5
x = 9

Therefore, the solutions to the system of equations are x = -5, y = 9 and x = 9, y = -5.