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4 years ago

What is the answer for m^2-5m-14=0?

Mathematics

1 answer:

tensa zangetsu [6.8K]4 years ago

3 0

Answer: m = 7 or -2

Step-by-step explanation:

Quadratic Formula! $\frac{{-b (+/-)\sqrt{(b^{2}-4ac }}}{2a}$

Polynomial Form: $ax^{2} +bx+c$

So in this example a: 1 b: -5 c: -14

You get: $\frac{{-(-5) (+/-)\sqrt{((-5)^{2}-4(1)(-14) }}}{2(1)}$

m = 7 or -2

Check by plugging a value back in for m

$(7)^{2} -5(7)-14=0?\\(-2)^{2} -5(-2)-14=0?\\$

True for both.

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Help me with A and B please

g100num [7]

Part A.

Ashwin had a 4-cm cube.

volume of cube = side^3

volume = (4 cm)^3 = 64 cm^3

Ashwin has 64 small cubes.

We need to find the volumes of all prisms in Part A. Only prisms with at most 64 cm^3 volume can be the answer.

A. v = 2 * 4 * 7 = 28

B. v = 4 * 5 * 6 = 120

C. v = 5 * 5 * 4 = 100

D. v = 4 * 7 * 5 = 140

E. v = 3 * 5 * 4 = 60

Part A. answer: A, E

Part B.

Dora had a 5-cm cube.

volume of cube = side^3

volume = (5 cm)^3 = 125 cm^3

Dora has 125 small cubes.

We need to find the volumes of all prisms in Part B. Only prisms with at most 125 cm^3 volume can be the answer.

A. v = 3 * 3 * 8 = 72

B. v = 3 * 4 * 5 = 60

C. v = 6 * 6 * 4 = 144

D. v = 5 * 8 * 4 = 160

E. v = 3 * 5 * 4 = 60

Part B. answer: A, B, E

6 0

3 years ago

A typical sugar cube has an edge length of 1.00 cm. Imagine you have a cubical box that contains a mole of sugar cubes, perfectl

alisha [4.7K]

Answer:

844368.7 m

Step-by-step explanation:

We are given that a typical sugar cube has an edge length of 1.00 cm.

We have to find the edge length of the box in meters.

Edge length of sugar cube=1 cm = $10^{-2}m$ ( $1 cm=\frac{1}{100}m$ )

Volume of a sugar cube= $side\times side\time side=(10^{-2})^3=10^{-6}m^3$

1 mole of sugar= $6.02\times 10^{23}units$

Volume of 1 unit= $10^{-6} m^3$

Volume of $6.02\times 10^{23}$ units= $6.02\times10^{23}\times 10^{-6}=6.02\times 10^{17} m^3$

Volume of box=1 mole of sugar= $6.02\times 10^{17} m^3$

Edge length of box= $\sqrt[3]{6.02\times 10^{17}}=844368.7 m$

6 0

3 years ago

Original price: $150; Markdown:40%(show work please)

zepelin [54]

Original price is $150 so you times 150 by 0.40
150 x 0.40 = 60
So you take the $150 and you subtract $60 from $150
150 - 60 = 90
So the answer is $90

8 0

3 years ago

Solve 5x^2 - 7x + 2 = 0 by completing the square.

Reika [66]

Answer: The correct option is (c) $\dfrac{49}{100}.$

Step-by-step explanation: We are given to solve the following quadratic equation by the method of completing the square:

$5x^2-7x+2=0~~~~~~~~~~~~~~~~~~~(i)$

Also, we are to find the constant added on both sides to form the perfect square trinomial.

We have from equation (i) that

$5x^2-7x+2=0\\\\\Rightarrow x^2-\dfrac{7}{5}x+\dfrac{2}{5}=0\\\\\\\Rightarrow x^2-2\times x\times \dfrac{7}{10}+\left(\dfrac{7}{10}\right)^2+\dfrac{2}{5}=\left(\dfrac{7}{10}\right)^2\\\\\\\Rightarrow \left(x-\dfrac{7}{10}\right)^2=\dfrac{49}{100}-\dfrac{2}{5}\\\\\\\Rightarrow \left(x-\dfrac{7}{10}\right)^2=\dfrac{49-40}{100}\\\\\\\Rightarrow \left(x-\dfrac{7}{10}\right)^2=\dfrac{9}{100}\\\\\\\Rightarrow x-\dfrac{7}{10}=\pm\dfrac{3}{10}\\\\\\\Rightarrow x=\pm\dfrac{3}{10}+\dfrac{7}{10}.$

So,

$x=\dfrac{3}{10}+\dfrac{7}{10},~~~~~~~~x=-\dfrac{3}{10}+\dfrac{7}{10}\\\\\\\Rightarrow x=\dfrac{10}{10},~~~~~~~~\Rightarrow x=\dfrac{-3+7}{10}\\\\\\\Rightarrow x=1,~-\dfrac{2}{5}.$

Thus, the required solution is $x=1,~-\dfrac{2}{5}.$ and the value of the constant added is $\dfrac{49}{100}.$

Option (c) is correct.

3 0

3 years ago

Hi! I just need help with the last problem, number 12. I did all of the rest. Please reply ASAP, thank you!

Fed [463]

Answer:

rocky???

Step-by-step explanation:

5/2 3/8

3 0

3 years ago