Question

A) y=x²+10 x-3б) y=-5x²-15x+7​

Answer 1

я это через photomaths сделала

Объяснение:

.

Answer 2

Ответ:

Объяснение:

A) y=x²+10 x-3

X²+10x-3=0

Δ=100+12=112   √Δ=√112=4√7

X1=(-10-4√7) / 2=-2(5+2√7)/2=-5-2√7

X2=(-10+4√7) /2=2(-5+2√7)/2=-5+2√7

б) y=-5x²-15x+7

-5x²-15x+7=0

Δ=225+140=365   ;  √Δ=V365

X1=(15-√365)/ (-10)

X2=(15+√365)/ (-10)

Answer 3

It looks like you've provided two quadratic equations. I'll help you analyze and work with each of them.

A) $y = x^2 + 10x - 3$

This is a quadratic equation in the form $ax^2 + bx + c$, where:

• $a = 1$
• $b = 10$
• $c = -3$

To work with this equation, you can find its vertex, axis of symmetry, and other relevant information. The vertex of a quadratic equation in the form $ax^2 + bx + c$ can be found using the formula:

$x_{\text{vertex}} = \frac{-b}{2a}$ $y_{\text{vertex}} = f(x_{\text{vertex}}) = a(x_{\text{vertex}})^2 + b(x_{\text{vertex}}) + c$

Substitute the values of $a$ and $b$ from your equation to find the vertex:

$x_{\text{vertex}} = \frac{-10}{2(1)} = -5$ $y_{\text{vertex}} = 1(-5)^2 + 10(-5) - 3 = 25 - 50 - 3 = -28$

So, the vertex of the parabola described by $y = x^2 + 10x - 3$ is $(-5, -28)$. The axis of symmetry is the vertical line passing through the vertex, which is $x = -5$.

B) $y = -5x^2 - 15x + 7$

This is another quadratic equation in the form $ax^2 + bx + c$, where:

• $a = -5$
• $b = -15$
• $c = 7$

You can also find the vertex of this equation using the same formula:

$x_{\text{vertex}} = \frac{-b}{2a}$ $y_{\text{vertex}} = f(x_{\text{vertex}}) = a(x_{\text{vertex}})^2 + b(x_{\text{vertex}}) + c$

Substitute the values of $a$ and $b$ from your equation to find the vertex:

$x_{\text{vertex}} = \frac{15}{2(-5)} = \frac{15}{-10} = -\frac{3}{2}$ $y_{\text{vertex}} = -5\left(-\frac{3}{2}\right)^2 - 15\left(-\frac{3}{2}\right) + 7 = -\frac{45}{4} + \frac{45}{2} + 7 = \frac{45}{4} + 7 = \frac{45}{4} + \frac{28}{4} = \frac{73}{4}$

So, the vertex of the parabola described by $y = -5x^2 - 15x + 7$ is $\left(-\frac{3}{2}, \frac{73}{4}\right)$. The axis of symmetry is the vertical line passing through the vertex, which is $x = -\frac{3}{2}$