Question

A)x + y = 7,(x2 - 9y = 7;​

Answer 1

Ответ:

Смотри решение на фото

Answer 2

To solve the system of equations:

1. x + y = 7
2. x^2 - 9y = 7

We can use the method of substitution. From the first equation, we can express x in terms of y:

x = 7 - y

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

(7 - y)^2 - 9y = 7

Expand the square:

49 - 14y + y^2 - 9y = 7

Combine like terms:

y^2 - 23y + 42 = 7

Subtract 7 from both sides:

y^2 - 23y + 35 = 0

Now, we need to factor this quadratic equation:

(y - 5)(y - 7) = 0

Setting each factor equal to zero:

1. y - 5 = 0 y = 5

2. y - 7 = 0 y = 7

Now that we have found the possible values of y, we can find the corresponding values of x using the first equation x + y = 7:

For y = 5: x + 5 = 7 x = 7 - 5 x = 2

For y = 7: x + 7 = 7 x = 7 - 7 x = 0

So, the solution to the system of equations is:

1. x = 2, y = 5
2. x = 0, y = 7