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
irina [24]
2 years ago
11

Long rationalise surds questions pls help​

Mathematics
1 answer:
Katena32 [7]2 years ago
3 0

Answer:

Noah mistakenly added 25 and 7 in denominator instead of subtracting in the third step.

Step-by-step explanation:

Noah had to rationalize the denominator of \frac{32}{5-\sqrt{7}}

According to him,

\frac{32}{5-\sqrt{7} = \frac{32(5+\sqrt{7}{(5-\sqrt{7})(5+\sqrt{7}

Solving the nominator and denominator

= \frac{160-32\sqrt{7}}{25+5\sqrt{7}-5\sqrt{7}-7}

Noah did correctly till this point.

In the next step he add 25 and 7 in the denominator, whereas, it should be subtracted.

Hence,

Noah mistakenly added 25 and 7 in denominator instead of subtracting in the third step.

You might be interested in
How many different 4 digit even numbers can be written using 0,5,6,3,8,7?<br><br> help asap please!!
fiasKO [112]

Step-by-step explanation:

I guess that means the digits can not be repeated in such a number.

let's start with how many numbers in general can be created :

we have 6 basic digits, and we are pulling 4 of them for a number.

if the sequence of the pulled digits would not matter, it would be combinations C (6, 4).

but we are creating different numbers, so the sequence of the digits does matter. so, it is permutations P (6, 4).

P(6, 4) = 6!/(6-4)! = 6!/2! = 6×5×4×3 = 360

so. bauxite, we can create 360 different 4 digit numbers out of these 6 digits.

but not all of them are wanted.

for example, I assume we don't want the numbers that start with a 0, because they would normally count as 3-digit numbers.

if that assumption is correct, we need to find how many would start with a 0, and subtract those from the total number.

since we are handling all 6 digits in the same way, an equal number must start with 0, with 5, with 6, with 3, with 8 and with 7.

so, 1/6 of the total number start with 0 : 360×1/6 = 60.

that means the total number of 4-digit numbers out of these 6 digits that do not start with 0 is 360-60 = 300.

but we are still not finished : we only want even numbers. that means they end with 0, 6 or 8.

in the same way we considered the first position, we consider also the last position. we have an equal amount of numbers that end with the different digits.

and so, we have 1/6 of 300 for each ending digit.

we want the specified 3 digits as end digits, so we get

3×1/6 of the 300 = 1/2 × 300 = 150

so, we can write 150 different 4-digit even numbers out of these 6 digits.

3 0
2 years ago
Nick had 3 1/4 bottles of water for his wrestling practice. When he finished he had 1 2/4 bottles of water left. He said he used
sweet-ann [11.9K]
1 2/4+2 1/4 ≠ 3 1/4 but 1 2/4+2 1/4 = 3 3/4
7 0
3 years ago
The sum of three numbers is 10. The first number minus the second plus the third is 6. The first minus the third is 2 more than
mina [271]
The answer to your question is 8
7 0
3 years ago
What is the answer to this question
Soloha48 [4]

(0,2),(-2,-1),(2,5)

-3x+2y=2

+3x    +3x

2y/2=3x+2/2

y=1 1/2x+2

Plug in numbers for x then solve for y

7 0
3 years ago
For the weight of the box that she measured, Beatriz determined the margin of error as 23.5 pounds to 24.5 pounds. What was the
Marat540 [252]
The greatest possible error is 0.5lb.

The GPE is one half of one unit, no matter which unit you're using or the margin of error you have.

Since we are using pounds in this case, the GPE is 0.5 pounds.
3 0
3 years ago
Read 2 more answers
Other questions:
  • Why can't you compare 5 minutes in 240 seconds without making some kind of change
    14·1 answer
  • The sum of two consecutive even integers is -298. What are the integers?
    6·1 answer
  • What is f(2) of the function?<br> F(x)=4x+1
    14·1 answer
  • What is the arc length if theta = 2pi / 3 and the radius is 4cm
    8·1 answer
  • The solution set of the inequality 2x − y &gt; 2 consists of all the points __ ? the line __ ?
    9·1 answer
  • Helppppppppppppppppp plzzzzzzzzzzz
    10·1 answer
  • The two triangles below are similar. What value of Q and B would make this true
    5·1 answer
  • Can some help me for number 25 where it says Evaluate this simplified polynomial for a=4 and b =-1. I don't understand it correc
    15·2 answers
  • What is 121% as a fraction then decimal
    14·2 answers
  • Sara threw 6 darts at this dartboard, and they all hit the target. Which of the following numbers could have been her score: 4,2
    6·2 answers
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!