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3 years ago

Number 21 please help! Thank you!

Mathematics

1 answer:

Nina [5.8K]3 years ago

4 0

7 x 3 = 21
7 + 7 +7 = 21
3 ÷ 7 = 21
21 - 7 = 3

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X minus 2 is equal to 7

Lerok [7]

X = 9

Add both values 7 + 2 = 9, which is x.

9 - 2 = 7.

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2 years ago

A credit card bill is best kept in which of the following places?

Minchanka [31]

Answer: SAFE DEPOSITE BOX

Step-by-step explanation:

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3 years ago

Read 2 more answers

What is the coefficient of x2y3 in the expansion of (2x + y)5?

Zigmanuir [339]

Option C:

The coefficient of $x^{2} y^{3}$ is 40.

Solution:

Given expression:

$(2 x+y)^{5}$

Using binomial theorem:

$(a+b)^{n}=\sum_{i=0}^{n}\left(\begin{array}{l}n \\i\end{array}\right) a^{(n-i)} b^{i}$

Here $a=2 x, b=y$

Substitute in the binomial formula, we get

$(2x+y)^5=\sum_{i=0}^{5}\left(\begin{array}{l}5 \\i\end{array}\right)(2 x)^{(5-i)} y^{i}$

Now to expand the summation, substitute i = 0, 1, 2, 3, 4 and 5.

$$=\frac{5 !}{0 !(5-0) !}(2 x)^{5} y^{0}+\frac{5 !}{1 !(5-1) !}(2 x)^{4} y^{1}+\frac{5 !}{2 !(5-2) !}(2 x)^{3} y^{2}+\frac{5 !}{3 !(5-3) !}(2 x)^{2} y^{3}$

$$+\frac{5 !}{4 !(5-4) !}(2 x)^{1} y^{4}+\frac{5 !}{5 !(5-5) !}(2 x)^{0} y^{5}$

Let us solve the term one by one.

$$\frac{5 !}{0 !(5-0) !}(2 x)^{5} y^{0}=32 x^{5}$

$$\frac{5 !}{1 !(5-1) !}(2 x)^{4} y^{1} = 80 x^{4} y$

$$\frac{5 !}{2 !(5-2) !}(2 x)^{3} y^{2}= 80 x^{3} y^{2}$

$$\frac{5 !}{3 !(5-3) !}(2 x)^{2} y^{3}= 40 x^{2} y^{3}$

$$\frac{5 !}{4 !(5-4) !}(2 x)^{1} y^{4}= 10 x y^{4}$

$$\frac{5 !}{5 !(5-5) !}(2 x)^{0} y^{5}=y^{5}$

Substitute these into the above expansion.

$(2x+y)^5=32 x^{5}+80 x^{4} y+80 x^{3} y^{2}+40 x^{2} y^{3}+10 x y^{4}+y^{5}$

The coefficient of $x^{2} y^{3}$ is 40.

Option C is the correct answer.

5 0

3 years ago

on monday,the price of one share of webb company stock was 24.85. by friday,the price was 25.004. by how much did the price chan

vredina [299]

Answer:

idk

Step-by-step explanation:

how about you do the math yourself

6 0

3 years ago

Find the measures of EAF DAE and CAD

sdas [7]

You have to build an equation to find the answer,

angles in a straight line add upto 180°
so your equation would be,

12x+30°=180°
-30 -30
=12x=150°
÷12 ÷12
=x=12.5°

now find the measures of the angles by using 12.5 as x.

angle EAF= 2x
=2×12.5
=25° degrees

angle DAE= 4x
=4×12.5
=50°degrees

angle CAD=6x
=6×12.5
=75°degrees

check,
30+25+50+75=180°degrees

hope this helps.......

7 0

3 years ago