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3 years ago

Factor the trinomial. You many need to check the discriminant to make sure it can be factored. SHOW YOUR WORK.

1 answer:

6 0

Check the discriminant (always a good idea).

b^2 - 4ac
b = -19
c = -15
a = 10

(-19)^2 - 4(10)(-15)
361 + 600
961

Yes it can be factored, but if you like, you could use the quadratic formula.
x = [- (-19) +/- sqrt(961)]/(2 * 10)
x = [19 +/- 31 ] / 20
x = (19 + 31/20
x = (50)/20
x = 5/2

x = [19 - 31] / 20
x = [- 12]/20
x = -3/5

Getting the factors is a little tricky.
(x - 5/2)(x + 3/5) = 0
The first factor is found by putting
x - 5/2 in that form and multiplying through by 2
1/2 (2x - 5) The 1/2 comes from multiplying by 2.

The second factor is
1/5 (5x + 3)

So the equation will look like
1/2(2x - 5)1/5(5x + 3) = 0 If you multiply by 2 you get
(2x - 5)1/5(5x + 3) = 0 and now multiply by 5 you get
(2x - 5) (5x + 3)

Check
2x*5x - 25x + 6x - 15
10x^2 - 19x - 15 = 0

So everything works out.

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Answer:

Use khan academy for the graph.

Step-by-step explanation:

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What's the lateral area of a right circular cone if the diameter of the base is 4 m and the slant height of the cone is 15m? Rou

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The formula for the lateral surface area of a right circular cone is:
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4 years ago

Write an expression for each of these expressions:

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Answer:

A. 36 ÷ a

B. 55 - b

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3 years ago

A California condor left its cliff-side nest and soared downwards at a rate of 16 meters per second. After 8 seconds, the bird s

fredd [130]

16m/s * 8s = 128m Multiply out the time to get the total displacement from the descent.

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1421m

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4 years ago

9.01 prove that the two circles are similar

il63 [147K]

Answer:

see the procedure

Step-by-step explanation:

we know that

Figures can be proven similar if one, or more, similarity transformations (reflections, translations, rotations, dilations) can be found that map one figure onto another.

In this problem to prove circle C and circle A are similar, a translation and a scale factor (from a dilation) will be found to map one circle onto another.

we have that

Circle C is centered at (0,-1) and has a radius of 2 units

Circle A is centered at (3,4) and has a radius of 5 units

step 1

Move the center of the circle C onto the center of the circle A

the transformation has the following rule

(x,y)--------> (x+3,y+5)

(0,-1)------> (0+3,-1+5)-----> (3,4)

center circle C is now equal to center circle A

The circles are now concentric (they have the same center)

step 2

A dilation is needed to increase the size of circle C to coincide with circle A

scale factor=radius circle A/radius circle C-----> 5/2=2.5

radius circle C will be=2*scale factor-----> 2*2.5=5 units

radius circle C is now equal to radius circle A

therefore

A translation, followed by a dilation will map one circle onto the other, thus proving that the circles are similar

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3 years ago