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3 years ago

On a final exam, Alex answered 21 out of 25 questions correctly. He

Mathematics

1 answer:

morpeh [17]3 years ago

4 0

Answer:

He needs to answer at least 20 questions correctly.

Step-by-step explanation:

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How much will cost to buy beef for a family of 5 if each person gets 1/2 pound of beef and the beef cost 5.99 per pound?

polet [3.4K]

Answer: 2.5 or 3

Step-by-step explanation:

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3 years ago

Solve 3x2 = −12x − 15. x = −4 ± 2i x = −4 ± i x = −2 ± 2i x = −2 ± i

diamong [38]

ANSWER

$x = - 2 \pm i$

EXPLANATION

We use the method of completing the squares.

The equation is
$3 {x}^{2} = - 12x - 15$

We rewrite the above equation to obtain;

$3 {x}^{2} + 12x = - 15$

We divide through by 3 to obtain;

${x}^{2} + 4x = - 5$

We add half the coefficient of
$x$

to both sides of the equation to get,

${x}^{2} + 4x + {2}^{2} = - 5 + {2}^{2}$

The right hand side is now a perfect square.

${(x + 2)}^{2} = - 1$

We now take square root of both sides to get;

$x + 2 = \pm \sqrt{ - 1}$

We add -2 to both sides,

$x = - 2 \pm \sqrt{ - 1}$

We simplify to obtain,

$x = - 2 \pm i$

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3 years ago

Helpmepleaseeeeeeee 1.

Vedmedyk [2.9K]

1. 7 2/9−4 2/3=2 5/9(Decimal: 2.555556)

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3 years ago

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Any help, please! I dont understand

frutty [35]

The answer would be 40% :)

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3 years ago

A certain ferry moves up and down a river between Town A and

Blizzard [7]

Answer: 60 miles

Step-by-step explanation:

Given

It takes ferry 2 hours to travel to town A and only $1.5\ hr$ to travel back to town B.

Speed of current is $u=5\ mph$

Suppose the speed of the ferry is $v$ mph

Distance traveled in both the cases is same, but it took more time traveling to city A that is, ferry is moving upstream and downstream for returning time.

$\Rightarrow 2(v-5)=1.5(v+5)\\\Rightarrow 2v-10=1.5v+7.5\\\Rightarrow 0.5v=17.5\\\Rightarrow v=35\ mph$

Distance between the towns is $2\times (35-5)=60\ \text{miles}$

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3 years ago

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