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3 years ago

Arlene us showing her work in simplifying(−7.9)+8.2−3.4+2.1 identify any error in her work or in her reasoning.

1 answer:

4 0

Keep doing each step manually, and see where it slips up: −7.9+8.2−3.4+2.1=−1 −7.9+8.2+(−3.4)+2.1=−1 −7.9+(−3.4)+8.2+2.1=−1 (−7.9+(−3.4))+(8.2+2.1)=−1 −11.3+10.3=−1

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What are two equivalent equations for x(5x-6)+13x-10

Naily [24]

5x^2 +7x -10

5x^2 (-6x + 13x) - 10

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2 years ago

The cost of a ticket to the circus is $19.00 for

DENIUS [597]

Answer:

The number of tickets bought is 1000 adults tickets and 700 children were present

Explanation:

Let the number of children and adults present in the circus be x and y respectively

According to question,

Then, x + y = 1700 ……………..equation (1)

And, cost of ticket to circus for children and adult be 19, 42 respectively

Total cost of ticket;

for adults = 42y; for children = 19x

19x + 42y = 55300 …………………equation (2)

Multiplying equation (1) by 19

19x + 19y = 32300 ……………… eqn (3)

Subtracting equation 1 and 3, we get

23y = 23000

y = 1000

putting this value in eq (1), we get x = 700

Therefore, 1000 adults and 700 children were present .

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2 years ago

Find the height of a right square pyramid that has a rectangular base area of 70 square units and a volume of 140 cubic units.

Lostsunrise [7]

Answer:

B. 6 units

Step-by-step explanation:

$V = {a}^{2} \frac{h}{3} \\ \\ 140 = 70( \frac{h}{3}) \\ \\ 6 = h \\ \\ 140 = 70(2)$

I am joyous to assist you anytime.

5 0

3 years ago

Find the exact value of the given expression. sin(2cos^-1(5/13))

xeze [42]

Answer:

+120/169 or -120/169

Step-by-step explanation:

let $cos^{-1}[\frac{5}{13} ] = \alpha$

where, alpha is some angle that satisfies the assumed condition.

so, $cos\alpha= 5/13$

[ taking cos to the other side or applying cos on both sides]

now, substitute this in the given expression

$sin(2cos^-1(5/13)) = sin(2\alpha )$

as sin $\beta$ = $+ or -\sqrt{1-(cos\beta) ^{2}$

[by general trigonometry formula: $cos^{2}[\beta] +sin^{2}[\beta]=1$ ]

so if $cos\alpha= 5/13$ , we can get sin $\alpha$ from the above formula as + or - 12/13

(because, after taking square root on both sides we keep + or -]

as, sin $2\beta = 2*sin[\beta ]*cos[\beta ]$

[by general trigonometry formula]

here, now $sin[2\alpha ]=2*(+or- 12/13)*5/13\\$

so, the final value can be 120/169 or -120/169.

4 0

3 years ago

Find the value of each variable in the parallelogram.

Nikitich [7]

Answer:

u = 4; v = 18

because this is a parallelogram

=> 2u + 2 = 5u - 10

6 = v/3

<=> 3u = 12

v = 6.3

<=> u = 4

v = 18

7 0

2 years ago