1answer.
Ask question
Login Signup
Ask question
All categories
  • English
  • Mathematics
  • Social Studies
  • Business
  • History
  • Health
  • Geography
  • Biology
  • Physics
  • Chemistry
  • Computers and Technology
  • Arts
  • World Languages
  • Spanish
  • French
  • German
  • Advanced Placement (AP)
  • SAT
  • Medicine
  • Law
  • Engineering
ziro4ka [17]
3 years ago
13

Evaluate 2x2 - 1 when x = 3.

Mathematics
2 answers:
Alla [95]3 years ago
6 0

Answer:11

Step-by-step explanation:2(3)x2-1=11

Charra [1.4K]3 years ago
4 0

Hello!

2.x^2 - 1 = 2.3^2 - 1 = 2.9 - 1 = 18-1 = 17

Good luck!

You might be interested in
How are the proofs the side length ratios of 30-60-90 and 45-45-90 triangles similar? How are they different?
Brut [27]

Solution:

Consider the Triangle ABC in which , ∠A=60°, ∠B=90°,∠C=30°

Let , Perpendicular =  P

We will use trigonometric ratio to prove that ratio of sides  will always be same by using either of angles that is 30° or 60°.

Sin C= \frac{\text{Perpendicular}}{\text{Hypotenuse}}

Sin 30°= \frac{1}{2}

So, Ratio of Perpendicular and Hypotenuse is always constant, that is always  \frac{1}{2}.

Therefore , Hypotenuse will be = 2 P

Now, using Pythagoras Theorem

⇒(Perpendicular)² + (Base)² = (Hypotenuse)²

⇒P²+ (Base)²=(2 P)²

⇒ (Base)²= 4 P²- P²

⇒(Base)²= 3 P²

⇒ Base= √3 P

So, ratio of Perpendicular to Base or Base to Perpendicular is \frac{1}{\sqrt{3}} or  \frac{\sqrt{3}}{1}.

Sin 60°= \frac{BC}{AC}=\frac{\sqrt3P}{P}=\frac{\sqrt3}{1}

⇒If you consider either angle of 30° or 60° to find the side length ratios, , then also ratio of sides is always that is  BC: AB or BC: AC or AB: AC →→ AB : BC : AC = 1 : √3 : 2 .

now, consider Triangle P QR, in which ∠P=∠R= 45°,∠Q=90°

To find the side length ratio we will use trigonometric ratio.

→Tan 45°= \frac{PQ}{QR}

→1= \frac{PQ}{QR}

→P Q= QR

Let , P Q= QR= K

Using Pythagoras theorem

⇒(Perpendicular)² + (Base)² = (Hypotenuse)²

⇒ K² + K²= (Hypotenuse)²

⇒(Hypotenuse)²= 2 K²

Hypotenuse= √2 K

⇒If you consider either angle that is of 45°  to find the side length ratios, , then also ratio of sides is always that is  P Q: QR or P Q: PR or QR: PR →→ P Q : QR : PR = 1 : 1:√2.

4 0
3 years ago
3/20 of what number is nine
Leviafan [203]
60.

You got backwards. Usually, you would divide by the bottom and multiply by the top. 

This time, you do 9 divided by 3 which is 3. Then 3 multiplied by 20 which is 60.
5 0
3 years ago
Read 2 more answers
Each Rubber ball is = to 2 balls btw, Find the median of the data in the pictograph below.
artcher [175]

Answer:

7

Step-by-step explanation:

The two in middle are 10 and 4

So add them both then divide by 2

So 14÷2

7

Hope this helps

8 0
3 years ago
Read 2 more answers
What is R?<br> i=v/R<br> What is ec?<br> i=ec/3
Juliette [100K]
R would be iv because you have to do cross multiplication.

ec would be 3 because you have to do cross multiplication.

6 0
4 years ago
Inez and Joel work at a store that sells
faltersainse [42]

Answer:

2 hrs and 32 mins

Step-by-step explanation:

Step 1. Because Inez worked more we are going to start by subtracting the the minutes. 23-51= -28.

Step 2. Now we move on to the hours. 7-4= 3. Know we know that the hour time is going to be three. But wait!

Step 3. Because we can't have negative numbers, we need to subtract some more. 60-28= 32. Now I know that my minutes will be 32.

Step 4. But because we used a negative number we have to subtract another hour from our time.

Answer: 2 hrs and 32 mins

Hope this helps!

7 0
3 years ago
Other questions:
  • What is the 10th term of the following geometric sequence?
    15·1 answer
  • Which of the following best represents the average rate at which the human hair grows?
    13·1 answer
  • How Would you graph, y=-7x+4
    13·1 answer
  • a number consisting of two digits make the sum of 10 if the digits are reversed the number is reduced by 36 find the number ​
    6·1 answer
  • What are the two consecutive whole. Numbers that the quotient for 42 divided by 9 is between?
    13·1 answer
  • Use function notation to write a recursive formula to represent the sequence: 3, 6, 12, … f(n) = f(n − 1) + 3 f(n) = f(n − 1) +
    7·2 answers
  • Which absolute value equation represents the graph
    5·1 answer
  • Please help with this question. Will give brainliest.
    15·1 answer
  • Freeeeeeeeeeeeeeeeeeeeeee points :)
    13·1 answer
  • What types of jobs did many of the first photographers have?
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!