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2 years ago

12

A science teacher needs to choose 4 students from a class of 20 to go to the library to do some research. How many different gro

ups can he select?

1 answer:

Marysya12 [62]2 years ago

8 0

20\4=5
Since there are 20 people and we want grps of 4

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Simplify the difference. (4w^2 – 4w – 8) – (2w^2 + 3w – 6)

Blababa [14]

Answer:

2w^2 -7w-2

Step-by-step explanation:

(4w^2 – 4w – 8) – (2w^2 + 3w – 6)

Distribute the minus sign

(4w^2 – 4w – 8) – 2w^2 - 3w + 6

I like to line them up vertically

4w^2 – 4w – 8

– 2w^2 - 3w + 6

-----------------------------

2w^2 -7w-2

8 0

3 years ago

Read 2 more answers

How do you solve this ?

Inga [223]

2.) y = x - 12

3.) 2x + 6

6 0

3 years ago

A sheet of glass has a density of

Alexxandr [17]

Answer:

2500 kg/m³

Step-by-step explanation:

Density of a material is the ratio of mass and volume of that material.

The S.I unit for density is grams per centimeters cubed (g/cm³) or kilograms per meter cubed (kg/m³)

Given density as 2.5 g/cm³ , convert to kg/m³

Formula is;

1g/cm³ = 1000 kg/m³

2.5 g/cm³=? cross-multiply

=2.5×1000 = 2500 kg/m³

7 0

2 years ago

Given the arithmetic sequence: u(1)= 124, u(2)= 117, u(3)= 110, u(4)=103,...

omeli [17]

We are given

arithmetic sequence: u(1)= 124, u(2)= 117, u(3)= 110, u(4)=103

so, first term is 124

u(1)= 124

now, we can find common difference

$d=u(2)-u(1)$

$d=117-124$

$d=-7$

now, we can find kth term

$u(k)=u(1)+(k-1)d$

now, we can plug values

and we get

$u(k)=124+(k-1)*-7$

$u(k)=124-7k+7$

$u(k)=131-7k$

u(k) must be negative

so,

$u(k)=131-7k$

$131-7k$

now, we can solve for k

$7k>131$

$k>18.714$

so, it's closest integer value is

$k=19$ ..............Answer

3 0

3 years ago

Solve equation by factoring.

3241004551 [841]

Hi ;-)

$x^2+6x-10=30 \ \ /-30\\\\x^2+6x-40=0\\\\a=1, \ b=6, \ c=-40\\\\\Delta=b^2-4ac=6^2-4\cdot1\cdot(-40)=36+160=196\\\\\sqrt{\Delta}=\sqrt{196}=14\\\\x_1=\frac{-b-\sqrt{\Delta}}{2a}=\frac{-6-14}{2}=\boxed{-10}\\\\x_2=\frac{-b+\sqrt{\Delta}}{2a}=\frac{-6+14}{2}=\boxed4$

8 0

2 years ago