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2 years ago

Please help!! I’m stuck on this

Mathematics

1 answer:

beks73 [17]2 years ago

7 0

Answer:

B. $x = -4\,\lor \,x = -1$

Step-by-step explanation:

Let $\sqrt{-4-5\cdot x} = x$ , we solve for $x$ by algebraic means.

1) $\sqrt{-4-5\cdot x} = x$ Given

2) $-4-5\cdot x = x^{2}$ Definition of power/Symmetry of equality

3) $x^{2}+5\cdot x + 4 = 0$ Compatibility with addition/Commutative and associative properties/Existence of additive inverse/Modulative property

4) $(x+4)\cdot (x+1) = 0$ $x^{2}+(a+b)\cdot x +a\cdot b = (x + a)\cdot (x+b)$

5) $x = -4\,\lor \,x = -1$ Result

Hence, the correct answer is B.

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3 years ago

Special right triangles.

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QUESTION 9

The given right angle triangle has its two legs equal to $x\:cm$ and the hypotenuse is $2\:units$ .

Using the Pythagoras theorem, we have

$x^2+x^2=2^2$

This implies that;

$2x^2=2^2$

$2x^2=4$

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$x=1.414$

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QUESTION 10

The given right angle triangle has its two legs equal to $x\:units$ and the hypotenuse is $7\:units$ .

Using the Pythagoras theorem, we have

$x^2+x^2=7^2$

This implies that;

$2x^2=7^2$

$2x^2=49$

$x^2=24.5$

$x=\sqrt{24.5}$

$x=4.95\:units$

QUESTION 11

Sam divided the square backyard into two sections along the 40ft diagonal.

Let one of the sides of the garden be $x\:units$ , then the other side of the garden is also $x\:units$ since it was a square backyard.

The diagonal is the hypotenuse which is 40ft and the two legs are $x\:units$ each.

Applying the Pythagoras Theorem, we have;

$x^2+x^2=40^2$

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$x^2=800$

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The length of one side of the garden is approximately 28cm.

QUESTION 12

The hypotenuse of Nicole's right triangular support is 92cm long.

It was given that the two lengths of the triangular support are of equal length.

Let the two lengths of the triangular support be $l\:cm$ each.

We then apply the Pythagoras theorem to obtain;

$l^2+l^2=92^2$

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$\Rightarrow l^2=4232$

$\Rightarrow l=\sqrt{4232}$

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Therefore Nicole needs $l+l=65.05cm+65.05cm\approx130cm$ of wood to complete the support.

The correct answer is A.

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A 45-45-90 triangle is an isosceles right triangle.

Let the length of the two legs be $m\:inches$ each.

It was given that the hypotenuse of this triangle is $12\:inches$ .

Applying the Pythagoras Theorem, we have;

$m^2+m^2=12^2$

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QUESTIONS 14.

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QUESTION 15.

The distance from third base to first base is also 127 ft to the nearest foot.

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What happens to the value of the expression 5/x+5 as x decreases from a large positive number to a small positive number?

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option 2. it increases

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