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ZanzabumX [31]
3 years ago
8

2x^2+9x=-7 Solve round to nearest tenth

Mathematics
1 answer:
Drupady [299]3 years ago
4 0

Answer:

  x = -3.5 or -1

Step-by-step explanation:

Add 7 and factor.

  2x^2 +9x +7 = 0

  (2x +7)(x +1) = 0

  x = -3.5   or   x = -1 . . . . . values that make the factors zero

_____

<em>Comment on factoring</em>

Factoring ax^2 +bx +c = 0 requires you find factors of ac that have a sum of b. Here, you're looking for factors of 2·7 = 14 that have a sum of 9. If you're observant, you realize that 2+7=9, so 2 and 7 are the factors you want.

Now, you can write the factored form as ...

  (ax +p)(ax +q)/a = 0 . . . . where p and q are the factors of ac we just found

The divisor "a" is used to simplify one or both of the factors. Here, we have ...

  (2x +2)(2x +7)/2 = 0

  (x +1)(2x +7) = 0 . . . . . . we removed a factor of 2 from the first binomial

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What is the quotient of 21.06 and 9​
bekas [8.4K]

Answer:

21.06÷9 = 2 and 36 left over

Step-by-step explanation:

5 0
2 years ago
A worker at a snack stand opened a new box of cups. The first day he used 30 cups , the second day the worker used 15 percent of
Sholpan [36]

Answer:

Step-by-step explanation:

the first day he used 30 cups

the second day he used 15% of the remaining cups...a total of 90 cups were used on second day.

so 15%of the remaining cups = 90.....so if u let x be the total cups, then the remaining cups would be x - 30

15% of (x - 30) = 90.....turn ur percent to a decimal..." of " means multiply

0.15(x - 30) = 90

0.15x - 4.5 = 90

0.15x = 90 + 4.5

0.15x = 94.5

x = 94.5 / 0.15

x = 630 total cups <==

lets check..

start with 630 cups....used 30 the first day....leaving u with 600 cups....15% of the remaining cups = 90.....so 15% of 600 = 90....lets check it

15%of 600 = 0.15(600) = 90...yep, thats correct....there were 630 cups in the new un-opened box

5 0
3 years ago
The Price family and the Jenkins family each used their sprinklers last summer. The water output rate for the Price family's spr
PIT_PIT [208]

Set up two equations:

1st:  P (for Price family) + J (for Jenkins family) = 45 hours

2nd: 20P + 35J = 1200 liters

Rewrite the first equation as P = 45 – J

Replace P in the second equation:

20(45-J) + 35J = 1200

Simplify:

900 -20J + 35J = 1200

900 +15J = 1200

Subtract 900 from both sides:

15J = 300

Divide both sides by 15:

J = 300/15

J = 20

Jenkins used theirs for 20 hours

Price used theirs for 45-20 = 25 hours.

7 0
2 years ago
You are designing a ramp where the horizontal distance is twice the vertical rise. what will be the ramp angle to the nearest te
ankoles [38]
Use the definition of tangent

or inv tangent (arctan or atan)

tan(theta) = opposite side/ adjacent side

the vertical rise would be the opposite side, the horozontal distance would be the adjacent side

let rise = y
let distance= x
x=2y

so tan(theta) = y/2y
tan(theta) = 1/2

theta = atan(1/2)

grab a handy dandy calculator, unless you know this conversion off the top of your head
7 0
3 years ago
A pizzeria sells a round pizza with a diameter of 16 inches. Another pizzeria sells a large square pizza with a side length of 1
ankoles [38]

Answer:

pizzeria1

Step-by-step explanation:

Given data

pizzeria1

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Area= πr^2

Area= 3.132*8^2

Area= 201.09 in^2

pizzeria2

Diameter=15in

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Area= πr^2

Area= 3.132*7.5^2

Area= 176.74n^2

4 0
3 years ago
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