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1 year ago

(Please someone help me!) (No links!) I don't know what to do!!

Mathematics

1 answer:

NeTakaya1 year ago

3 0

Answer:

the answer is the last one

Step-by-step explanation:

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Please help, this will just take a minute of your time ❤︎ (literally) (Discriminant Worksheet)

igomit [66]

Answer:

$\large\boxed{x=-\dfrac{7-\sqrt{97}}{4}\ \vee\ x=-\dfrac{7+\sqrt{97}}{4}}$

Step-by-step explanation:

$ax^2+bx+c=0\\\\\Delta=b^2-4ac\\\\\text{if}\ \Delta0,\ \text{then an equation has two solutions:}\ x=\dfrac{-b\pm\sqrt\Delta}{2a}\\\\\text{We have:}\\\\-2x^2-7x+10=4\qquad\text{subtract 4 from both sides}\\\\-2x^2-7x+6=0$

$a=-2,\ b=-7,\ c=6\\\\\Delta=(-7)^2-4(-2)(6)=49+48=97>0\\\\\sqrt\Delta=\sqrt{97}\\\\x=\dfrac{-(-7)\pm\sqrt{97}}{2(-2)}=\dfrac{7\pm\sqrt{97}}{-4}=-\dfrac{7\pm\sqrt{97}}{4}$

6 0

2 years ago

Root 3 cosec140° - sec140°=4 prove that

Lorico [155]

Answer:

Step-by-step explanation:

We are to show that $\sqrt{3} cosec140^{0} - sec140^{0} = 4\\$

Proof:

From trigonometry identity;

$cosec \theta = \frac{1}{sin\theta} \\sec\theta = \frac{1}{cos\theta}$

$\sqrt{3} cosec140^{0} - sec140^{0} \\= \frac{\sqrt{3} }{sin140} - \frac{1}{cos140} \\= \frac{\sqrt{3}cos140-sin140 }{sin140cos140} \\$

From trigonometry, 2sinAcosA = Sin2A

$= \frac{\sqrt{3}cos140-sin140 }{sin140cos140} \\\\= \frac{\sqrt{3}cos140-sin140 }{sin280/2}\\= \frac{4(\sqrt{3}/2cos140-1/2sin140) }{2sin280}\\\\= \frac{4(\sqrt{3}/2cos140-1/2sin140) }{sin280}\\since sin420 = \sqrt{3}/2 \ and \ cos420 = 1/2 \\ then\\\frac{4(sin420cos140-cos420sin140) }{sin280}$

Also note that sin(B-C) = sinBcosC - cosBsinC

sin420cos140 - cos420sin140 = sin(420-140)

The resulting equation becomes;

$\frac{4(sin(420-140)) }{sin280}$

= $\frac{4sin280}{sin280}\\ = 4 \ Proved!$

3 0

2 years ago

ll the members of a construction crew work at the same pace. Six of them working together are able to pour foundation in 22 hour

Cloud [144]

Answer:

44 hours

Step-by-step explanation:

Decreasing the people by a factor of 2 means we have 3 people

The job takes 6* 22 = 132 people hours

When we decrease the people, it will take more hours

132 people hours = 3 people * t hours

Divide each side by 3

132/3 = 3t/3

44 = t

It will take 44 hours

8 0

2 years ago

Factor completely. Please show and explain steps!

Fudgin [204]

3x² (6x² - 13x - 5) =

3x² (2x - 5) (2x+1) .

3 0

2 years ago

Help please I’ll give brainleiest :)

Paladinen [302]

Answer:

1 hour would be 10 $ each

Step-by-step explanation:

1)$10

2)$50

3)$80

I hope this helps

4 0

2 years ago