All categories

2 years ago

Need help I’m very confused

Mathematics

1 answer:

ololo11 [35]2 years ago

5 0

Shshhshshshuzhzhzususuusususu

You might be interested in

Question 1

drek231 [11]

QUESTION 1

We want to expand $(x-2)^6$ .

We apply the binomial theorem which is given by the formula

$(a+b)^n=^nC_0a^nb^0+^nC_1a^{n-1}b^1+^nC_2a^{n-2}b^2+...+^nC_na^{n-n}b^n$ .

By comparison,

$a=x,b=-2,n=6$ .

We substitute all these values to obtain,

$(x-2)^6=^6C_0x^6(-2)^0+^6C_1x^{6-1}(-2)^1+^6C_2x^{6-2}(-2)^2+^6C_3x^{6-3}(-2)^3+^6C_4x^{6-4}(-2)^4+^6C_5x^{6-5}(-2)^5+^6C_6x^{6-6}(-2)^6$ .

We now simplify to obtain,

$(x-2)^6=^nC_0x^6(-2)^0+^6C_1x^{5}(-2)^1+^6C_2x^{4}(-2)^2+^6C_3x^{3}(-2)^3+^6C_4x^{2}(-2)^4+^6C_5x^{1}(-2)^5+^6C_6x^{0}(-2)^6$ .

This gives,

$(x-2)^6=x^6-12x^{5}+60x^{4}-160x^{3}(-2)^3+240x^{2}-1925x+64$ .

Ans:C

QUESTION 2

We want to expand

$(x+2y)^4$ .

We apply the binomial theorem to obtain,

$(x+2y)^4=^4C_0x^4(2y)^0+^4C_1x^{4-1}(2y)^1+^4C_2x^{4-2}(2y)^2+^4C_3x^{4-3}(2y)^3+^4C_4x^{4-4}(2y)^4$ .

We simplify to get,

$(x+2y)^4=x^4(2y)^0+4x^{3}(2y)^1+6x^{2}(2y)^2+4x^{1}(2y)^3+x^{0}(2y)^4$ .

We simplify further to obtain,

$(x+2y)^4=x^4+8x^{3}y+24x^{2}y^2+32x^{1}y^3+16y^4$

Ans:B

QUESTION 3

We want to find the number of terms in the binomial expansion,

$(a+b)^{20}$ .

In the above expression, $n=20$ .

The number of terms in a binomial expression is $(n+1)=20+1=21$ .

Therefore there are 21 terms in the binomial expansion.

Ans:C

QUESTION 4

We want to expand

$(x-y)^4$ .

We apply the binomial theorem to obtain,

$(x-y)^4=^4C_0x^4(-y)^0+^4C_1x^{4-1}(-y)^1+^4C_2x^{4-2}(2y)^2+^4C_3x^{4-3}(-y)^3+^4C_4x^{4-4}(-y)^4$ .

We simplify to get,

$(x+2y)^4=^x^4(-y)^0+4x^{3}(-y)^1+6x^{2}(-y)^2+4x^{1}(-y)^3+x^{0}(-y)^4$ .

We simplify further to obtain,

$(x+2y)^4=x^4-4x^{3}y+6x^{2}y^2-4x^{1}y^3+y^4$

Ans: C

QUESTION 5

We want to expand $(5a+b)^5$

We apply the binomial theorem to obtain,

$(5a+b)^5=^5C_0(5a)^5(b)^0+^5C_1(5a)^{5-1}(b)^1+^5C_2(5a)^{5-2}(b)^2+^5C_3(5a)^{5-3}(b)^3+^5C_4(5a)^{5-4}(b)^4+^5C_5(5a)^{5-5}(b)^5$ .

We simplify to obtain,

$(5a+b)^5=^5C_0(5a)^5(b)^0+^5C_1(5a)^{4}(b)^1+^5C_2(5a)^{3}(b)^2+^5C_3(5a)^{2}(b)^3+^5C_4(5a)^{1}(b)^4+^5C_5(5a)^{0}(b)^5$ .

This finally gives us,

$(5a+b)^5=3125a^5+3125a^{4}b+1250a^{3}b^2+^250a^{2}(b)^3+25a(b)^4+b^5$ .

Ans:B

QUESTION 6

We want to expand $(x+2y)^5$ .

We apply the binomial theorem to obtain,

$(x+2y)^5=^5C_0(x)^5(2y)^0+^5C_1(x)^{5-1}(2y)^1+^5C_2(x)^{5-2}(2y)^2+^5C_3(x)^{5-3}(2y)^3+^5C_4(x)^{5-4}(2y)^4+^5C_5(x)^{5-5}(2y)^5$ .

We simplify to get,

$(x+2y)^5=^5C_0(x)^5(2y)^0+^5C_1(x)^{4}(2y)^1+^5C_2(x)^{3}(2y)^2+^5C_3(x)^{2}(2y)^3+^5C_4(x)^{1}(2y)^4+^5C_5(x)^{0}(2y)^5$ .

This will give us,

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

Ans:A

QUESTION 7

We want to find the 6th term of $(a-y)^7$ .

The nth term is given by the formula,

$T_{r+1}=^nC_ra^{n-r}b^r$ .

Where $r=5,n=7,b=-y$

We substitute to obtain,

$T_{5+1}=^7C_5a^{7-5}(-y)^5$ .

$T_{6}=-21a^{2}y^5$ .

Ans:D

QUESTION 8.

We want to find the 6th term of $(2x-3y)^{11}$

The nth term is given by the formula,

$T_{r+1}=^nC_ra^{n-r}b^r$ .

Where $r=5,n=11,a=2x,b=-3y$

We substitute to obtain,

$T_{5+1}=^{11}C_5(2x)^{11-5}(-3y)^5$ .

$T_{6}=-7,185,024x^{6}y^5$ .

Ans:D

QUESTION 9

We want to find the 6th term of $(x+y)^8$ .

The nth term is given by the formula,

$T_{r+1}=^nC_ra^{n-r}b^r$ .

Where $r=5,n=8,a=x,b=y$

We substitute to obtain,

$T_{5+1}=^8C_5(x)^{8-5}(y)^5$ .

$T_{6}=56a^{3}y^5$ .

Ans: A

We want to find the 7th term of $(x+4)^8$ .

The nth term is given by the formula,

$T_{r+1}=^nC_ra^{n-r}b^r$ .

Where $r=6,n=8,a=x,b=4$

We substitute to obtain,

$T_{6+1}=^8C_5(x)^{8-6}(4)^6$ .

$T_{7}=114688x^{2}$ .

Ans:A

4 0

2 years ago

What is the x-and y-intercept of the graph 4x -5y =40??

umka21 [38]

Answer:

x-intercept = 10

y-intercept = -8

Step-by-step explanation:

$4x-5y=40$

To identify the y-intercept, we will need to format the equation in the form $y=mx+b$ . We can start by subtracting $4x$ from both sides of the equation:

$-5y=-4x+40$

Divide both sides of the equation by the coefficient of $y$ , which is $-5$ :

$y=\frac{-4}{-5} x - 8$

The $b$ is representative of the y-intercept in $y=mx+b$ .

Identify $b$ in the equation $y=\frac{-4}{-5} x - 8$ :

$b=-8$

Therefore, our y-intercept is -8.

To solve for the x-intercept, replace the $y$ in the equation $y=\frac{-4}{-5} x - 8$ with a zero:

$0=\frac{-4}{-5} x - 8$

Add $8$ to both sides of the equation:

$8=\frac{-4}{-5} x$

You can go ahead and divide $-4$ by $-5$ to get rid of the fraction:

$8=0.8x$

Divide both sides of the equation by the coefficient of $x$ , which is $0.8$ :

$10=x$

Therefore, our x-intercept is 10.

8 0

3 years ago

Two exponential functions are shown in the table. A 3-column table has 5 rows. The first column is labeled x with entries 2, 1,

DanielleElmas [232]

Answer:

B. The functions f(x) and g(x) are reflections over the y-axis.

Step-by-step explanation:

From the information given the table appears as;

x f(x)=2^x g(x)=0.5^x

2 4 0.25

1 2 0.5

0 1 1

-1 0.5 2

-2 0.25 4

Plotting the two graphs to view the trends;

In the graph of f(x)=2^x against x you notice a curve with increasing positive slope.

In the graph of g(x)=0.5^x against x you notice a curve with a negative slope that is increasing.

In combining both graphs you notice that f(x) and g(x) are reflections over the y-axis.

Correct answer is ;The functions f(x) and g(x) are reflections over the y-axis.

9 0

3 years ago

What does n mean in -10(n-5)=40

sergejj [24]

Distribute -10
-10n - 50 = 40
Add 50 to both sides
-50 + 50 would cancel
- 50 + 40 = -10
Divide by -10
-10/-10 = 1
N=1

3 0

2 years ago

Read 2 more answers

What is 4,967 divided by 68 with a remainder no decimals

Sonja [21]

The answer would be 73 remainder 0 if rounded to one decimal place

5 0

3 years ago

Read 2 more answers