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2 years ago

How many times does the graph of the function below interect or touch the x-axis? y=-2x^2+3x+5

Mathematics

1 answer:

Andrei [34K]2 years ago

7 0

Answer:

Two times at (-1,0) and (2.5,0)

Step-by-step explanation:

When the graph intersects or touches x-axis, y is equal to 0

so y = -2x^2 + 3x + 5

=> 0 = -2x^2 + 3x + 5

The formula to solve a quadratic equation of the form ax^2 + bx + c = 0 is equal to x = [-b +/-√(b^2 - 4ac)]/2a

so a = -2

b = 3

c = 5

substitute in the formula

x = [-3 +/- √(3^2 - 4x-2x5)]/2(-2)

x = [-3 +/- √(9 + 40)]/(-4)

x = [-3 +/- 7]/(-4)

x1 = (-3 + 7)/(-4) = 4/-4 = -1

x2 = (-3 - 7)/(-4) = -10/-4 = 5/2 = 2.5

so the graph has two x-intercepts (-1,0) and (2.5,0), therefore it intersects x-axis two times

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Which expressions show the expanded form for 200.06 choose all answers that are correct.

Anit [1.1K]

a. 2 x 100 0 x 1 0 x 1/10 6 1/100b. 2 x 100 0 x 1 0 x 1/100 6 1/1000

Hope it helps! :D

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2 years ago

Six sophomores and 14 freshmen are competing for two alternate positions on the debate team. Which expression represents the pro

Elanso [62]

Answer:

Choose the first alternative

$\displaystyle P=\frac{_{1}^{6}\textrm{C}\ _{1}^{5}\textrm{C}}{_{2}^{20}\textrm{C}}$

Step-by-step explanation:

Probabilities

The requested probability can be computed as the ratio between the number of ways to choose two sophomores in alternate positions $(N_s)$ and the total number of possible choices $(N_t)$ , i.e.

$\displaystyle P=\frac{N_s}{N_t}$

There are 6 sophomores and 14 freshmen to choose from each separate set. There are 20 students in total

We'll assume the positions of the selections are NOT significative, i.e. student A/student B is the same as student B/student A.

To choose 2 sophomores out of the 6 available, the first position has 6 elements to choose from, the second has now only 5

$_{1}^{6}\textrm{C}\ _{1}^{5}\textrm{C} \text{ ways to do it}$

The total number of possible choices is

$_{2}^{20}\textrm{C} \text{ ways to do it}$

The probability is then

$\boxed{\displaystyle P=\frac{_{1}^{6}\textrm{C}\ _{1}^{5}\textrm{C}}{_{2}^{20}\textrm{C}}}$

Choose the first alternative

7 0

2 years ago

Read 2 more answers

Due to a leak, the amount of water in a pool is decreasing by 5858 gal every hour.

Dafna1 [17]

Here is the solution to the given problem above.
Given the the amount of water in a pool is decreasing 5/8 gallon every hour.
And what would be the change in the number of gallons after 3/4 hour. So what we are going to do is just to multiply 5/8 by 3/4. And the result would be 15/32. The total change in the number of gallons of water in the pool after 3/4 hour would be 15/32 gallons.

4 0

2 years ago

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Oliga [24]

To find the area of a complex shape:

⇒ must split into simpler shapes

a rectangle of 8m by 7m
a rectangle of 2m by 8 m

Now let's find:

Area of a rectangle of 8m by 7m

$Area=8*7=56m^2$

Area of a rectangle of 2m by 8m

$Area = 2 * 8 = 16m^2$

Total Area = 56 + 16 = 72 m²

Answer: 72 m²

Hope that helps!

6 0

1 year ago

Please i need this due now and DO NOT GIVE ME A LINK FOR THE ANSWER

lana66690 [7]

Answer:

Y = -3(x - 5/6)^2 - 59/12 and x = 5±i√59/6

Step-by-step explanation:

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2 years ago