solve the system of equations y=2x^2-3 y=3x-1

7 answers

To solve the system of equations:

y = 2x^2 - 3
y = 3x - 1

We can set the two equations equal to each other:

2x^2 - 3 = 3x - 1

Rearranging the equation:

2x^2 - 3x + 2 = 0

To solve this quadratic equation, we can use factoring, completing the square, or the quadratic formula. In this case, let's use the quadratic formula:

x = (-b ± √(b^2 - 4ac)) / (2a)

For our equation:

a = 2, b = -3, and c = 2

Substituting these values into the quadratic formula:

x = (-(-3) ± √((-3)^2 - 4(2)(2))) / (2(2))
x = (3 ± √(9 - 16)) / 4
x = (3 ± √(-7)) / 4

Since we have a negative value under the square root, the equation has no real solutions. Therefore, the system of equations has no real solutions.
how many real numbers solutions are there to the equation 0=-3x^2+x-4
To determine the number of real number solutions to the equation:

0 = -3x^2 + x - 4

We can use the discriminant (b^2 - 4ac) of the quadratic equation. In this case, the equation is in the form ax^2 + bx + c = 0.

Comparing our equation to this form, we have:

a = -3
b = 1
c = -4

The discriminant is given by:

D = b^2 - 4ac

Substituting the values:

D = (1)^2 - 4(-3)(-4)
D = 1 - 48
D = - 47

Since the discriminant is negative (D < 0), there are no real number solutions to the equation.
solve the equation by completing the square if necessary round to the nearest hundredth x^2-18x=19
To solve the equation by completing the square:

x^2 - 18x = 19

First, we need to rewrite the equation so that the x terms are grouped together. We can do this by adding (18/2)^2 = 81 to both sides of the equation:

x^2 - 18x + 81 = 19 + 81
x^2 - 18x + 81 = 100

Now, we can express the left side of the equation as a perfect square:

(x - 9)^2 = 100

Taking the square root of both sides:

√((x - 9)^2) = ±√(100)

Simplifying:

x - 9 = ±10

To solve for x, we can separate the equation into two cases:

Case 1:
x - 9 = 10
x = 10 + 9
x = 19

Case 2:
x - 9 = -10
x = -10 + 9
x = -1

Therefore, the equation has two solutions: x = 19 and x = -1.
solve x^2-81=0
To solve the equation x^2 - 81 = 0:

We can rewrite the equation as (x - 9)(x + 9) = 0.

From here, we can set each factor equal to zero and solve for x:

x - 9 = 0 or x + 9 = 0

For x - 9 = 0, adding 9 to both sides gives us:

x = 9

For x + 9 = 0, subtracting 9 from both sides gives us:

x = -9

Therefore, the equation has two solutions: x = 9 and x = -9.