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3 years ago

PLS HELP AND DONT PUT LINKS

Mathematics

1 answer:

Verdich [7]3 years ago

8 0

Answer:

add more pts to get answered

Step-by-step explanation:

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A university has 750 female students and 2250 male students. Thirty per cent of female students study chemistry and 60% of male

UNO [17]

Answer:

1/7 or 14.3%

Step-by-step explanation:

30% of 750 = 225 (females who study chemistry)

60% of 2250 = 1350 (males who study chemistry)

1575 = total students studying chemistry

P (female chemistry student) = 225/1575 = 1/7 (simplified)

1/7 = 14.3%

7 0

2 years ago

A Create a linear expression

frez [133]

Answer:

(2x+A)(2x+B) = 4x2 + (2B+ 2A)x + AB. Trial and error gives the factorization 4x2 - 3x - 10 - (4x+5)(x- 2) .Step-by-step explanation:

3 0

3 years ago

In a right triangle ABC, CD is an altitude, such that AD=BC. Find AC, if AB=3 cm, and CD= 2 cm.

konstantin123 [22]

Consider right triangle ΔABC with legs AC and BC and hypotenuse AB. Draw the altitude CD.

1. Theorem: The length of each leg of a right triangle is the geometric mean of the length of the hypotenuse and the length of the segment of the hypotenuse adjacent to that leg.

According to this theorem,

$BC^2=BD\cdot AB.$

Let BC=x cm, then AD=BC=x cm and BD=AB-AD=3-x cm. Then

$x^2=(3-x)\cdot 3,\\ \\x^2=9-3x,\\ \\x^2+3x-9=0,\\ \\D=3^2-4\cdot (-9)=9+36=45,\\ \\\sqrt{D}=\sqrt{45}=3\sqrt{5},\\ \\x_1=\dfrac{-3-3\sqrt{5} }{2}0.$

Take positive value x. You get

$AD=BC=\dfrac{-3+3\sqrt{5} }{2}\ cm.$

2. According to the previous theorem,

$AC^2=AD\cdot AB.$

Then

$AC^2=\dfrac{-3+3\sqrt{5} }{2}\cdot 3=\dfrac{-9+9\sqrt{5} }{2},\\ \\AC=\sqrt{\dfrac{-9+9\sqrt{5} }{2}}\ cm.$

Answer: $AC=\sqrt{\dfrac{-9+9\sqrt{5} }{2}}\ cm.$

This solution doesn't need CD=2 cm. Note that if AB=3cm and CD=2cm, then

$CD^2=AD\cdot DB,\\ \\2^2=AD\cdot (3-AD),\\ \\AD^2-3AD+4=0,\\ \\D$

This means that you cannot find solutions of this equation. Then CD≠2 cm.

8 0

3 years ago

Read 2 more answers

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aleksandr82 [10.1K]

Bro i don’t know either

3 0

3 years ago

The square root of a number is between 8 and 9. Which of the following could be the value of that number? Select all that apply.

ser-zykov [4K]

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7 0

3 years ago