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3 years ago

Help me pleaseeeeeeeeeeeeee

Mathematics

2 answers:

SIZIF [17.4K]3 years ago

7 0

Answer:

(1,2)

Step-by-step explanation:

5x+2y = 9

3x -2y = -1

------------------------

Add them together

5x+2y = 9

3x -2y = -1

------------------------

8x = 8

Divide each side by 8

8x/8 = 8/8

x=1

Now we can find y

5x+2y =9

5(1) +2y = 9

5+2y = 9

Subtract 5 from each side

5-5+2y = 9-5

2y =4

Divide each side by 2

2y/2 = 4/2

y =2

gregori [183]3 years ago

5 0

Answer:x=1 y=2

Step-by-step explanation:

you add and get 8x=8 x=1 so plugging in one you get 5+2y=9 so 4=2y so y=2

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You roll a die. If an odd number comes up, you lose. If you get a 6, you win $60. If it is aneven number other than 6, you get t

vitfil [10]

Answer:

Step-by-step explanation:

Given that if an odd number comes up, you lose.

i.e. $P(losing) = P(1,3,5) = \frac{1}{2}$

$P(win 60) = P(6) =\frac{1}{6} \\$

If you get 2 or 4 you roll again

Thus rolling again prob = $\frac{2}{6} =\frac{1}{3}$

After rolling II time, if get 6, win otherwise lose.

Thus winning amounts A canbe

0 36 60

$P(0) = \frac{1}{2}+\frac{1}{3} (\frac{5}{6})=\frac{7}{9} \\P(36) = \frac{1}{3} (\frac{1}{6})=\frac{1}{18}\\P(60) =\frac{1}{6}$

This is a genuine pdf since prob >0 and total prob = 1.

b)Expected gain = sum of gain * prob = $\frac{7}{9} (0)+\frac{1}{18} (36)+\frac{1}{6} (60)\\=12$

Thus I would be willing to pay an amount atmost 12 dollars.

6 0

3 years ago

The half-life of a radioactive kind of europium is 9 years. How much will be left after 18 years, if you start with 40 grams of

Viktor [21]

Answer:There will be 10 grams left because you subtract half of the current amount from it every 9 years.

Step-by-step explanation:

6 0

3 years ago

Round 9118 to the nearest ten

gavmur [86]

(8)=ones place

(1)0=tens place

(1)00=hundreds place

(9)000=thousands place

The "1" beside the 8, is the tenths spot so you would round that part of the number.

Therefore the answer would be:

9120

6 0

3 years ago

What is the solution to this system of linear equations?

Eva8 [605]

8x+y=3
-8x -8x
--------------
y=-8x+3

7x-2y=-6
-7x -7x
------------------
-2y=-7x-6
----- -------
-2 -2
y=7/2x+3

Substitute -8x+3 in place of y
-8x+3=7/2x+3
+8x +8x
-----------———
3= 11.5x+3
-3 -3
———————
0 = 11.5x
—— ——
11.5 11.5

X=0

8x+y=3
8(0)+y=3
0+y=3
y=3

Check
8(0)+3=3
7(0)-2(3)=-6
0-6=-6

Answer is choice B

3 0

4 years ago

Since BC is parallel to DE, triangles ABC and ADE are similar. What are the lengths of the unknown sides?

NikAS [45]

Answer:

Step-by-step explanation:

Step 1: find BC

Given Triangles ABC and ADE are similar,

$\frac{AB}{AD}$ = $\frac{BC}{DE}$

BC = $\frac{AB}{AD}$ x DE

= $\frac{8}{8 + 4}$ x 9

= 6 cm

Step 2: use Pythagorean theorem to find AC and / or AE

Consider triangle ABC,

by Pythagorean theorem,

AB² + BC² = AC²

AC² = 6² + 8² = 100

AC = √100 = 10 (answer... we can see that C is the only one with AC=10.

Step 3: Verify.. even though we know that it is C because AC = 10, you can verify that the ansewer is correct by finding CE and confirming that CE=5

By using similar triangles ABC and ADE,

AC/AE = AB / AD

AE = AD/AB x AC = 12/8 x 10 = 15

CE = AE - AC = 15 - 10 = 5 (answer confirmed)

5 0

3 years ago