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3 years ago

What is -x^2 if x=-2

Mathematics

2 answers:

maksim [4K]3 years ago

8 0

4. You substitute the x with -2, which means the problem is -(-2^2).

yanalaym [24]3 years ago

4 0

Answer:

-4

Step-by-step explanation:

plug in -2

-(-2)^2 = -4

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LuckyWell [14K]

Answer:

1st - Yes ; 2nd - Yes ; 3rd - Yes ; 4th - No

Step-by-step explanation:

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3 years ago

50 POINTS!!! In rectangle ABCD, AB = 6 cm, BC = 8 cm, and DE = DF. The area of triangle DEF is one-fourth the area of rectangle

aalyn [17]

Answer:

$EF=4\sqrt{3}$

Step-by-step explanation:

In rectangle ABCD, AB = 6, BC = 8, and DE = DF.

ΔDEF is one-fourth the area of rectangle ABCD.

We want to determine the length of EF.

First, we can find the area of the rectangle. Since the length AB and width BC measures 6 by 8, the area of the rectangle is:

$A_{\text{rect}}=8(6)=48\text{ cm}^2$

The area of the triangle is 1/4 of this. Therefore:

$\displaystyle A_{\text{tri}}=\frac{1}{4}(48)=12\text{ cm}^2$

The area of a triangle is half of its base times its height. The base and height of the triangle is DE and DF. Therefore:

$\displaystyle 12=\frac{1}{2}(DE)(DF)$

Since DE = DF:

$24=DF^2$

Thus:

$DF=\sqrt{24}=\sqrt{4\cdot 6}=2\sqrt{6}=DE$

Since ABCD is a rectangle, ∠D is a right angle. Then by the Pythagorean Theorem:

$(DE)^2+(DF)^2=(EF)^2$

Therefore:

$(2\sqrt6)^2+(2\sqrt6)^2=EF^2$

Square:

$24+24=EF^2$

Add:

$EF^2=48$

And finally, we can take the square root of both sides:

$EF=\sqrt{48}=\sqrt{16\cdot 3}=4\sqrt{3}$

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3 years ago

Read 2 more answers

Determine whether the cost for ordering multiple items that will be delivered is sometimes, always or never proportional. Explai

Tanzania [10]

It could sometimes be proportional. The reasoning here is that if all the items have different prices it won't be, however if the items you are ordering all have the same price they will be!

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3 years ago

MATH HELP ME ASAP PLEASE

elena55 [62]

Answer:

53lbs.

Step-by-step explanation:

If Kevin bought 3 20lbs. Bags of gravel he would have 60 lbs. of gravel. In the end he has 7 lbs. of gravel left he used 53 pounds.

Equations:

7+x=60 or 60-7=53 lbs.

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3 years ago

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D= kA [T2 - T1 / L] Solve for T1

mel-nik [20]

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3 years ago