Same amount as 2 hundreds + 14 tens +3 ones please help

73 POINTS! PLEASE HELP

zzz [600]

Answer:

6) B

7) E

8) D

9) A

10) C

6 0

3 years ago

Solve (x + 3)2 + (x + 3) – 2 = 0. Let u = Rewrite the equation in terms of u. (u2 + 3) + u – 2 = 0 u2 + u – 2 = 0 (u2 + 9) + u –

Verdich [7]

Answer:

The solutions of the original equation are x=-5 and x=-2

Step-by-step explanation:

we have

$(x+3)^2+(x+3)-2=0$

Let

$u=(x+3)$

Rewrite the equation

$(u)^2+(u)-2=0$

Complete the square

$u^2+u=2$

$u^2+u+1/4=2+1/4$

$u^2+u+1/4=9/4$

rewrite as perfect squares

$(u+1/2)^2=9/4$

square root both sides

$(u+1/2)=\pm\frac{3}{2}$

$u=(-1/2)\pm\frac{3}{2}$

$u=(-1/2)+\frac{3}{2}=1$

$u=(-1/2)-\frac{3}{2}=-2$

the solutions are

u=-2,u=1

Alternative Method

The formula to solve a quadratic equation of the form

$ax^{2} +bx+c=0$

is equal to

$x=\frac{-b\pm\sqrt{b^{2}-4ac}} {2a}$

in this problem we have

$(u)^2+(u)-2=0$

so

$a=1\\b=1\\c=-2$

substitute in the formula

$u=\frac{-1\pm\sqrt{1^{2}-4(1)(-2)}} {2(1)}$

$u=\frac{-1\pm\sqrt{9}} {2}$

$u=\frac{-1\pm3} {2}$

$u=\frac{-1+3} {2}=1$

$u=\frac{-1-3} {2}=-2$

the solutions are

u=-2,u=1

Find the solutions of the original equation

For u=-2

$-2=(x+3)$ ----> $x=-2-3=-5$

For u=1

$1=(x+3)$ ----> $x=1-3=-2$

therefore

The solutions of the original equation are

x=-5 and x=-2

4 0

3 years ago

Read 2 more answers

Help with 25,27,and 28

dedylja [7]

Answer:

For 25, the answer is C

Step-by-step explanation:

How I got the answer for 25 is:

To find the mean absolute deviation of the data, start by finding the mean of the data set.

How you do this is first you need to find the sum of the data values, (add all the numbers together) and divide the sum by the number of data values.(and divide that number by how many numbers you added together in the first place)

In this case, we'd be adding 44 + 39 + 47 + 38 + 38 + 41 + 40, and that equals 287. Now we'll divide 287 by how many numbers we added together, which is 7 numbers. 287 ÷ 7 = 41. That's the mean of the data set.

Next, we'll find the absolute deviation of the mean. How we do this is, we find how far away all the numbers are from 41.

44 is 3 away from 41

39 is 2 away from 41

47 is 6 away from 41

38 is 3 away from 41

41 is 0 away from 41

40 is 1 away from 41

So now, we add all of the distances together (3, 2, 6, 3, 0, and 1), and that equals 15! Now we do 15 ÷ 6, which is 2.5 and the reason we're dividing by 6 is because we're dividing by the number of distances we added together. Now, if you look on your worksheet, the closest answer to 2.5 is C, (2.6) so I'd chose that as the correct answer. I hope that helped!

4 0

3 years ago

Find x on the triangle

iragen [17]

Answer:

(c)

Step-by-step explanation:

Using the cosine ratio in the right triangle

cos42° = $\frac{adjacent}{hypotenuse}$ = $\frac{x}{12}$