To find where on the hill the canonball lands
So 0.15x = 2 + 0.12x - 0.002x^2
Taking the LHS expression to the right and rearranging we have -0.002x^2 + 0.12x -
0.15x + 2 = 0.
So we have -0.002x^2 - 0.03x + 2 = 0
I'll multiply through by -1 so we have
0.002x^2 + 0.03x -2 = 0.
This is a quadratic eqn with two solutions x1 = 25 and x2 = -40 since x cannot be negative x = 25. The second solution y = 0.15 * 25 = 3.75

8 0

3 years ago

Given that 3x-y : x+2y = 2 : 5, Determine the ratio x:y

N76 [4]

Answer:

x : y = 9 : 13

Step-by-step explanation:

Given that

3x - y : x + 2y = 2 : 5

Express the ratio in fractional form, that is

$\frac{3x-y}{x+2y}$ = $\frac{2}{5}$ ( cross- multiply )

5(3x - y) = 2(x + 2y) ← distribute parenthesis on both sides )

15x - 5y = 2x + 4y ( subtract 2x from both sides )

13x - 5y = 4y ( add 5y to both sides )

13x = 9y ( divide both sides by 13 )

x = $\frac{9}{13}$ y ( divide both sides by y )

$\frac{x}{y}$ = $\frac{9}{13}$ , that is

x : y = 9 : 13

7 0

4 years ago

I need help working this out

Leona [35]

I think in this situation the best method would be a guess and check. You know that there are 8 dimes more than there are nickels. So just keep increasing each number by one until you reach $1.40. If there were 9 dimes and 1 nickels it would add up to $0.95. If there were 10 dimes and 2 nickels, it would add up to $1.10. If there were 11 dimes and 3 nickels, it would add up to $1.25. If there were 12 dimes and 4 nickels, it would add up to $1.40. So your answer is 12 dimes and 4 nickels.

I hope this helped!

8 0

3 years ago

Read 2 more answers

(08.07 HC)

andreev551 [17]

Answer:

$\textsf{A)} \quad x=-2, \:\:x=\dfrac{5}{2}$

$\textsf{B)} \quad \left(\dfrac{1}{4},-\dfrac{81}{8}\right)=(0.25,-10.125)$

C) See attachment.

Step-by-step explanation:

Given function:

$f(x)=2x^2-x-10$

To factor a <u>quadratic</u> in the form $ax^2+bx+c$ <em> , </em>find two numbers that multiply to $ac$ and sum to $b$ :

$\implies ac=2 \cdot -10=-20$

$\implies b=-1$

Therefore, the two numbers are -5 and 4.

Rewrite $b$ as the sum of these two numbers:

$\implies f(x)=2x^2-5x+4x-10$

Factor the first two terms and the last two terms separately:

$\implies f(x)=x(2x-5)+2(2x-5)$

Factor out the common term (2x - 5):

$\implies f(x)=(x+2)(2x-5)$

The x-intercepts are when the curve crosses the x-axis, so when y = 0:

$\implies (x+2)(2x-5)=0$

Therefore:

$\implies (x+2)=0 \implies x=-2$

$\implies (2x-5)=0 \implies x=\dfrac{5}{2}$

So the x-intercepts are:

$x=-2, \:\:x=\dfrac{5}{2}$

The x-value of the vertex is:

$\implies x=\dfrac{-b}{2a}$

Therefore, the x-value of the vertex of the given function is:

$\implies x=\dfrac{-(-1)}{2(2)}=\dfrac{1}{4}$

To find the y-value of the vertex, substitute the found value of x into the function:

$\implies f\left(\dfrac{1}{4}\right)=2\left(\dfrac{1}{4}\right)^2-\left(\dfrac{1}{4}\right)-10=-\dfrac{81}{8}$

Therefore, the vertex of the function is:

$\left(\dfrac{1}{4},-\dfrac{81}{8}\right)=(0.25,-10.125)$

Plot the x-intercepts found in Part A.

Plot the vertex found in Part B.

As the <u>leading coefficient</u> of the function is positive, the parabola will open upwards. This is confirmed as the vertex is a minimum point.

The axis of symmetry is the <u>x-value</u> of the <u>vertex</u>. Draw a line at x = ¹/₄ and use this to ensure the drawing of the parabola is <u>symmetrical</u>.

Draw a upwards opening parabola that has a minimum point at the vertex and that passes through the x-intercepts (see attachment).

5 0

2 years ago