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3 years ago

How to factor 5x^2 +4x -1

1 answer:

4 0

$5x^2+4x-1\\\\Method\ 1:\\\\5x^2+4x-1=5x^2+5x-x-1=5x(x+1)-1(x+1)\\=(x+1)(5x-1)\\\\5x^2+4x-1=(x+1)(5x-1)\\\\Method\ 2:\\\\5x^2+4x-1\\a=5;\ b=4;\ c=-1\\\\\Delta=b^2-4ac\\\\\Delta=4^2-4\cdot5\cdot(-1)=16+20=36 \ \textgreater \ 0\\\\x_1=\dfrac{-b-\sqrt\Delta}{2a}\ and\ x_2=\dfrac{-b+\sqrt\Delta}{2a}\\\\\sqrt\Delta=\sqrt{36}=6\\\\x_1=\dfrac{-4-6}{2\cdot5}=\dfrac{-10}{10}=-1\\\\x_2=\dfrac{-4+6}{2\cdot5}=\dfrac{2}{10}=0.2\\\\5x^2+4x-1=5(x-0.2)(x+1)=(5x-1)(x+1)$

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8 miles is approximately equal to 6 km how many km are equal to 28 miles ? How many miles are equal to 42km

Snowcat [4.5K]

28/8 = 3.5

3.5*6 = 21 km

42/6=7

7*8 = 56 miles

7 0

2 years ago

Can someone help me plzz??

ki77a [65]

Answer:

(0,20)

Step-by-step explanation:

1) we can represent the situation as coordinates

lets have # of texts be "x" variable

lets have bill be "y" as the y variable is always the dependant variable and the cost of the phone bill is dependant upon the number of texts so

y=mx+b-slope-intercept form

coordinates: (50,25) and (100,30)

slope: (30-25)/(100-50)

5/50=1/10

hence slope=1/10

y=1/10x+b

substitute in a coordinate pair into this equation

25=50*1/10+b

25=5+b

b=20

hence y intercept is (0,20)

8 0

2 years ago

Determine whether the three segment lengths will produce a triangle. Type yes or no in the space provided.

tresset_1 [31]

Answer:

20 , 20 , 30 will produce a triangle

Step-by-step explanation:

* Lets study how to know if the lengths of the three segments

can formed a triangle

- It is a fact that in any triangle the sum of the smallest two sides

must be greater than the largest side

- Lets study some examples

# If the lengths of the three segments are 5 , 6 , 7

∵ 5 and 6 are the smallest

∴ 5 + 6 = 11

∵ 11 > 7 ⇒ the sum greater than the 3rd side

∴ 5 , 6 , 7 can formed a triangle

# If the lengths of the three segments are 5 , 7 , 12

∵ 5 and 7 are the smallest

∴ 5 + 7 = 12

∵ 12 = 12 ⇒ the sum equal the 3rd side

∴ 5 , 7 , 12 can not formed a triangle

# If the lengths of the three segments are 10 , 12 , 24

∵ 10 and 12 are the smallest

∴ 10 + 12 = 22

∵ 22 < 24 ⇒ the sum less than the 3rd side

∴ 10 , 12 , 24 can not formed a triangle

* Now lets solve the problem

∵ The length of the three segments are 20 , 20 , 30

∵ 20 and 20 are the smallest

∴ 20 + 20 = 40

∵ 40 > 30 ⇒ the sum greater than the 3rd side

∴ 20 , 20 , 30 will produce a triangle

5 0

2 years ago

Solve the system of equations using the substitution method.

Karolina [17]

Substitution is where we first Isolate one of the unknowns, express it in terms of the other unknown, and replace the isolated unknown with the other unknown in another equation. So that each time we only need to deal with one unknown. I think you'll get a better idea here:

First name these 2 equations with 1 and 2.
4x + 5y = 7 (1)
y = 3x + 9 (2)

Since y is already isolated in (2), so we can skip the isolation step and continue to substitute.

Substitute (2) into (1).
4x + 5(3x+9) = 7

Expand.
4x + 15x + 45 = 7

Group.
19x + 45 = 7

Shift +45 to the other side and turn it into -45.

19x = 7 - 45
19x = -38

Shift x19 to the other side, turn it into /19.
X = - 38/19
X = - 2

Now we solved x already, we can just substitute x= - 2 back to equation (2).

y = 3(-2) + 9
y = - 6 + 9
y = 3

So, the answers are
x = - 2
y = 3

3 0

2 years ago

. Let f(p) be the average number of days a house stays on the market before being sold for price p in $1,000s. Which statement b

Umnica [9.8K]

Answer: a.This is the average number of days the house stayed on the market before being sold for $150,000.

Step-by-step explanation:

Given: f(p) be the average number of days a house stays on the market before being sold for price p in $1,000s.

To find the meaning f(150),

here p= 150 which means f(150) is the average number of days a house stays on the market before being sold for price 150 in $1,000s.

And 150 in $ 1,000= $150,000

Therefore, f(150) is the average number of days a house stays on the market before being sold for price $150,000.

7 0

3 years ago

Read 2 more answers