Ask question

Ask question

All categories

3 years ago

5

Translate the following phrase into an expression:The difference between 20 and twice of a number twice of a number

1 answer:

Vitek1552 [10]3 years ago

7 0

Answer: probably D

In math difference means subtraction

Step-by-step explanation:

You might be interested in

5x = –25 + 5y <br><br> 10y = 42 + 2x

Novay_Z [31]

To solve this equation there are many ways you can do to solve. One way is to simply substitute one variable for another.

5x = 5y - 25
X = y - 5

10y = 42 + 2x
10y = 42 + 2(y - 5)
10 y = 42 + 2y - 10
8y = 32
Y = 4.

X = y - 5
X = 4 - 5
X = -1.

P(X,y) = P(-1,4). This would be the solution or the point where they would intersect.

3 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

<em>Alternative Method</em>

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

<em>Find the solutions of the original equation</em>

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

When finding the 9th term in a geometric sequence with a common ratio of 2 and a first

Zarrin [17]

Answer:

8

Step-by-step explanation:

Nth term of a geometric sequence is given as:

$t_n = a r^{(n-1)}$ ...(1)

Plugging n = 9, a = 3 and r = 2 in the above equation, we find:

$t_9 = (3) (2)^{9-1}$

$t_9 = (3) (2)^{8}$ ... (2)

Comparing equations (1) & (2), we obtan:

(n - 1) = 8

5 0

3 years ago

Please help! this is timed!

Scilla [17]

Answer: -8-10

Step-by-step explanation:

4 0

3 years ago

Read 2 more answers

Identify three of the key messages used by advertisers when promoting their products.

Dmitry_Shevchenko [17]

Answer:

Three key messages often used are: 1. "Everyone is doing it"; 2. "It's fun to use our products"; 3. "You will be successful if you use our products."

Step-by-step explanation:

hope it helps

4 0

3 years ago

Read 2 more answers