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
Lady bird [3.3K]
3 years ago
12

Show your solution follow the steps need an answer, please need an answer, please.​

Mathematics
2 answers:
VladimirAG [237]3 years ago
7 0

Step-by-step explanation:

21. x² - 4x - 5 > 0

→ (x - 5) (x - 1) > 0

{x - 5 > 0

{x + 1 > 0

{x - 5 < 0

{x + 1 < 0

{x > 5

{x > -1

{x < 5

{x < -1

= x < -1 or x > 5

therefore, option A is correct

22). 4p² - 1 ≤ 0

(2p - 1) (2p + 1) ≤ 0

{2p - 1 ≤ 0

{2p + 1 ≥ 0

{2p - 1 ≥ 0

{2p + 1 ≤ 0

{p ≤ 1/2

{p ≥ -1/2

{p ≥ 1/2

{p ≤ -1/2

1/2 ≤ p ≤ 1/2

{p ≥ 1/2

{p ≤ -1/2

-1/2 ≤ p ≤ 1/2

therefore, option A is correct.

23). y < 3x² + 3x - 6

3x² + 3x - 6 = 0

3x² + 6x - 3x - 6 = 0

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

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

x = -2, 1

this is the correct ans. but their is no option similar to it.

25. x and y are root of

m² - 11m + 18 = 0

hence, x + y = 11

xy = 18

2xy = 36

now, x² + y²

= (x +y)² - 2xy

= (11)² - 36

= 121 - 36

= 85

therefore, option A is correct.

26. x² - 2x - 120

(x -1)² - 1 - 1² = 0

(x -1)² = 1 + 1²

x - 1² = 2

x - 1 = ±√2

1 ± √2

therefore, option A is correct.

hope this answer helps you dear..take care!

Artemon [7]3 years ago
3 0

Answer:

Step-by-step explanation:

21) x² - 4x - 5 > 0

x² - x + 5x - 5 > 0

x(x - 1) + 5(x - 1) > 0

(x - 1) (x + 5) > 0

x - 1 >0   or  x + 5 > 0

x > 1       or  x > - 5    Ans: D

22)  4p² ≤ 1

p² ≤ 1/4

p ≤ 1/2  or  p ≥ -1/2

-1/2  ≥ p ≤ 1/2

23)y < 3x² + 3x - 6

(1 , -7)

x = 1  and y = -7

-7 < 3*1 + 3*1 - 6

-7 < 3 + 3 - 6

-7 < 0

(1 , -7) satisfies the equation.

Option b

24) 5x² - 7x = 0

a = 5  ; b = -7  ;c = 0

Discriminant = b² - 4ac =  49 - 0 = 0

x = \dfrac{-b+\sqrt{D}}{2a}   \ ; \  \dfrac{-b-\sqrt{D}}{2a}\\\\x = \dfrac{7+\sqrt{49}}{10} ; \dfrac{7-\sqrt{49}}{10}\\\\x = \dfrac{7+7}{10};\dfrac{7-7}{10}\\\\x =\dfrac{14}{10} ; 0\\\\x = \dfrac{7}{5}; 0

x = 0 ; x = 7/5  Option a)

25) m² - 11 m + 18 = 0

m² - 2m - 9m + (-9)*(-2) = 0

m(m - 2) - 9(m - 2) = 0

(m - 2)(m - 9) = 0

m = 2 , 9

x = 2 and y =9

x² + y² = 2² + 9² = 4 + 81 = 85   Option a)

26) x² - 2x - 1 = 0

Add the constant 1 to both sides

x² - 2x = 1

Divide the coefficient of x by 2.  2/2 = 1. Now add this 1 to both sides of the equation.

x² - 2x  + 1  = 1+1

x² - 2x + 1 = 2

(x - 1)² = 2

Take square root

x - 1 = ±√2

x  = 1 ± √2    Option a)

You might be interested in
The population of an island is 6000 people this year and is projected to be 6300 people next year, by what percentage is the pop
Julli [10]

Answer:

5% increase

Step-by-step explanation:

First, find how much it increased:

6300 - 6000

= 300

Then, to find the percent increase, divide 300 by 6000

300/6000

= 0.05

So, there was a 5% increase in the population

8 0
4 years ago
Given: N is the midpoint of LQ,
nlexa [21]

Answer:

6. SAS Postulate

5. ASA Postulate

Step-by-step explanation:

7 0
3 years ago
Read 2 more answers
Can somebody prove this mathmatical induction?
Flauer [41]

Answer:

See explanation

Step-by-step explanation:

1 step:

n=1, then

\sum \limits_{j=1}^1 2^j=2^1=2\\ \\2(2^1-1)=2(2-1)=2\cdot 1=2

So, for j=1 this statement is true

2 step:

Assume that for n=k the following statement is true

\sum \limits_{j=1}^k2^j=2(2^k-1)

3 step:

Check for n=k+1 whether the statement

\sum \limits_{j=1}^{k+1}2^j=2(2^{k+1}-1)

is true.

Start with the left side:

\sum \limits _{j=1}^{k+1}2^j=\sum \limits _{j=1}^k2^j+2^{k+1}\ \ (\ast)

According to the 2nd step,

\sum \limits_{j=1}^k2^j=2(2^k-1)

Substitute it into the \ast

\sum \limits _{j=1}^{k+1}2^j=\sum \limits _{j=1}^k2^j+2^{k+1}=2(2^k-1)+2^{k+1}=2^{k+1}-2+2^{k+1}=2\cdot 2^{k+1}-2=2^{k+2}-2=2(2^{k+1}-1)

So, you have proved the initial statement

4 0
3 years ago
Harry rode 2 1/2 miles on his bike yesterday. He rode 1 3/4 miles on his bike today. If he plans to ride 6 miles this week on hi
aksik [14]

Answer:

1 3/4 miles

Step-by-step explanation:

2 1/2+ 1 3/4= 4 1/4

6-4 1/4= 1 3/4

3 0
3 years ago
Read 2 more answers
Please I need some help on this
jeyben [28]

Answer:

Step-by-step explanation: a

8 0
3 years ago
Read 2 more answers
Other questions:
  • If 5 4, − = x then x =<br> A. −21<br> B. −11<br> C. 1<br> D. 11
    9·1 answer
  • How to order -14.4, -14, -14 1/5 from least to greatest
    7·1 answer
  • Often in statistics research, a population is too large to collect data on. A sampling distribution of a statistic is created by
    15·1 answer
  • Is this graph a direct proportion? #math
    6·1 answer
  • What is 3 2/3 divided by 2 1/6
    14·1 answer
  • 5 ft
    8·1 answer
  • The problems are in the pictures
    12·2 answers
  • What is the volume of the figure shown?
    13·1 answer
  • 99-7a^2 when a =3 please help!!!!!!!!!
    9·1 answer
  • The number of bank robberies that occur in Lagos is modeled to be Poisson distributed with mean of 1.8 per day. Find the probabi
    5·1 answer
Add answer
Login
Not registered? Fast signup
Signup
Login Signup
Ask question!