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2 years ago

Find the coefficient of x^2 in the expansion of (2x-1)^7

1 answer:

7 0

(2x-1)^7
=(2x)^7+7(2x)^6(-1)+21(2x)^5(-1)^2+35(2x)^4(-1)^3+35(2x)^3(-1)^4+21(2x)(-1)^5+7(2x)(-1)^6+(-1)^7
=128x^7+7(64x^6)(-1)+21(32x^5)+35(16x^4)(-1)+35(8x^3)+21(4x^2)(-1)+14x-1
=128x^7-7(64x^6)+672x^5-35(16x^4)+280x^3-21(4x^2)+14x-1
=128x^7-448x^6+672x^5-560x^4+280x^3-84x^2+14x-1
The coefficient of x^2 is -84

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in triangle ABC shown below, L is the midpoint of BC, M is the midpoint of AB, and N is the midpoint of AC. Find the perimeter o

alexdok [17]

since m and n are the midpoints of ab and ac resistively

then ,bc=2mn=16

since m and l are the midpoints of ba and bc respectively

then, ac =2mn =10

then,nc =1/2 × 10 =5

similary, mb=6

then ,perimeter=nc+mb+mn+bc=5+6+8+16=35

6 0

3 years ago

Solve for p: -9 + p < 15 <br> A. p > 24 B. -p > 6 C. p < 24 D. -p < -6

Soloha48 [4]

Answer:

C. In the given expression -9 + p < 15 , the value of p < 24.

Step-by-step explanation:

Here, the given expression is :

-9 + p < 15

Now, solving for the value of p.

If equals are added to both sides of inequality, the inequality remains unchanged.

Now, -9 + p < 15

⇒ -9 + p + 9 < 15 + 9 (adding +9 on both sides)

or, p < 24

Hence, in the given expression -9 + p < 15 the value of p < 24.

5 0

3 years ago

3 points

garri49 [273]

Answer:

j=8

Step-by-step explanation:

30-6=24 divived by 3 = 8 which means jordans age is 8 and matthew is 16

5 0

2 years ago

PLSS HURRY FOR 50 POINTS

serg [7]

A !!!!!!!!!!!!!!!!!!!

7 0

2 years ago

Read 2 more answers

Emma has money into savings accounts. One rate is 8% and the other is 12%. If she has $450 more in the 12% account and the total

AveGali [126]

Let's say that the value invested in the account with a rate of 8% is "x", then the amount invested in the account with a rate of 12% is:

$x+450$

To calculate the total interest we need to calculate the interest of each individual account and sum them:

$\begin{gathered} \frac{8}{100}\cdot x=0.08\cdot x \\ \frac{12}{100}\cdot(x+450)=0.12\cdot x+54 \end{gathered}$

The total interest is the sum of the two expressions above:

$\begin{gathered} 220=(0.08\cdot x)+(0.12\cdot x+54) \\ 220=0.08\cdot x+0.12\cdot x+54 \\ 220-54=0.2\cdot x \\ 166=0.2\cdot x \\ 0.2\cdot x=166 \\ x=\frac{166}{0.2} \\ x=830 \end{gathered}$

The value invested in the account with 8% interest is 830, the one invested in the account with 12% interest is 1280.

7 0

10 months ago