What is the length of the indicated side?<br><br>

Members of a college chemistry department agree to contribute equal amounts of money to make up a scholarship fund of $280. Then

Zarrin [17]

Answer:

7 members

Step-by-step explanation:

Lets say that the department has n members. If each member contributes with an equal amount x and make a total of $280, we know that:

n*x = 280

Where each one colaborated with:

n*x/n = 280/n

Or what is the same that: (as the n on the left eliminate themselves)

x = 280/n (*)

Now the department hires 3 more members, so we now have n+3 members. And we know that the pass from contributing x to contribute $30 less, it is, x-30 (I omit the $ symbol for simplicity). So, know we have:

x-30 = 280/(n+3)

We can replace x here by the formulation of x we did in the (*) equation:

( 280/n) - 30 = 280/(n+3)

using common denominator:

( 280/n) - 30 n/n = 280/(n+3)

( 280 - 30 n)/n = 280/(n+3)

Cross multiplying the denominators:

( 280 - 30 n)*(n+3) = 280*(n)

280n - 30n^2 + 840 - 90n = 280n

Subtracting 280 n in both sides:

30n^2 + 840 - 90n = 0

Dividing both sides by 30:

-n^2 - 3n + 28 = 0

Factorizing this term (you can notice the factor immediately or solving with baskara resolution, I omit the baskara for simplicity):

-(n + 7)(n - 4) =0

So, n is equal to 4 and -7. As we are dealing with people we can not have -7 people, so we keep only n=4.

So, previous the new hiring there were 4 members, now there are 7.

The used to collaborate with 280/4 = $70, now the collaborate with 280/7=$40, and we see the collaboration decreased in $30.

7 0

3 years ago

An ice cream cone has a height of 4 in and a radius of 1 in. If the cone is 0.1 in thick, what is the difference (in in3) betwee

SSSSS [86.1K]

Answer:

$0.79 in^3$

Step-by-step explanation:

Given data for the cone

height h= 4 in

radius r= 1 in

hence diameter d= 2 in

thickness of cone= 0.1 in

The volume of the cone including the shell can be expressed as

$volume=\frac{1}{3} \pi r^2h$

$volume= \frac{1}{3}*3.142*1^2*4\\\volume= \frac{12.568}{3} \\\volume= 4.189 in^3$

The volume of the ice cream can be expressed as

N/B: the diameter of the ice cream is

2-(0.1*2)= 2-0.2= 1.8 in

hence the radius is 0.9 in

$volume= \frac{1}{3}*3.142*0.9^2*4\\\ volume= \frac{10.18}{3} \\\ volume= 3.39 in^3$

The difference in volume is $4.189-3.39= 0.79 in^3$

8 0

3 years ago

Henry buys an item for $4.23. He gives the cashier a $20 bill. How much money should Henry get back?

N76 [4]

Answer:

Henry will get $15.77 back.

Step-by-step explanation:

20 - 4.23 = 15.77

7 0

3 years ago

Triangle ABC is translated according to the rule (x, y) = (x+2y-S). If the coordinates of the pre-image of point B are

Liula [17]

The coordinates of b is 1.9

7 0

3 years ago

Prove that a triangle with the sides a - 1 cm to root under a

vivado [14]

Question is Incomplete, Complete question is given below.

Prove that a triangle with the sides (a − 1) cm, 2√a cm and (a + 1) cm is a right angled triangle.

Answer:

∆ABC is right angled triangle with right angle at B.

Step-by-step explanation:

Given : Triangle having sides (a - 1) cm, 2√a and (a + 1) cm.

We need to prove that triangle is the right angled triangle.

Let the triangle be denoted by Δ ABC with side as;

AB = (a - 1) cm

BC = (2√ a) cm

CA = (a + 1) cm

Hence,

${AB}^2 = (a -1)^2$

Now We know that

$(a- b)^2 = a^2+b^2 - 2ab$

So;

${AB}^2= a^2 + 1^2 -2\times a \times1$

${AB}^2 = a^2 + 1 -2a$

Now;

${BC}^2 = (2\sqrt{a})^2= 4a$

Also;

${CA}^2 = (a + 1)^2$

Now We know that

$(a+ b)^2 = a^2+b^2 + 2ab$

${CA}^2= a^2 + 1^2 +2\times a \times1$

${CA}^2 = a^2 + 1 +2a$

${CA}^2 = AB^2 + BC^2$

[By Pythagoras theorem]

$a^2 + 1 +2a = a^2 + 1 - 2a + 4a\\\\a^2 + 1 +2a= a^2 + 1 +2a$

Hence, ${CA}^2 = AB^2 + BC^2$

Now In right angled triangle the sum of square of two sides of triangle is equal to square of the third side.

This proves that ∆ABC is right angled triangle with right angle at B.

4 0

3 years ago

What is the length of the indicated side?​

What is the length of the indicated side?