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3 years ago

F(x) = -2x + 9, find x if f(x) = 23

Mathematics

1 answer:

JulijaS [17]3 years ago

7 0

Answer:

x = -7

Step-by-step explanation:

f(x) = -2x + 9

f(x) = 23

therefore, f(x) =

-2x + 9 = 23

-2x = 23 - 9

-2x = 14

-x = 14 ÷ 2

-x = 7

x = -7

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Jobisdone [24]

Answer:

B. A cow of 5 years is predicted to produce 5.5 more gallons per week.

Step-by-step explanation:

Let $M(a) = 40.8-1.1\cdot a$ , where $a$ is the age of the dairy cow, measured in years, and $M(a)$ is the predicted milk production, measured in gallons per week.

Besides, we consider $a_{1}$ and $a_{2}$ , such that $a_{1}\ne a_{2}$ , we define the difference between predicted milk productions ( $\Delta M$ ) below:

$\Delta M = -1.1\cdot (a_{2}-a_{1})$ (1)

If we know that $a_{1} = 5\,yr$ and $a_{2} = 10\,yr$ , then the difference between predicted milk productions is:

$\Delta M = -1.1\cdot (10-5)$

$\Delta M = -5.5\,\frac{gal}{week}$

That is, a cow of 5 years is predicted to produce 5.5 more gallons per week than a cow of 10 years. Hence, the right answer is B.

6 0

3 years ago

F equals to 2 f - 20

ICE Princess25 [194]

Answer:

Step-by-step explanation:

f = 2f - 20

f - 2f = - 20

- f = - 20

f = 20

7 0

3 years ago

Find the discriminant and determine the nature of the roots to the quadratic equation

Katen [24]

№17
$x^{2} +6x-7=0 \\ D=6 ^{2} -4*(-7)=36+28=64=8 ^{2} \\ \\ x_{1} = \frac{-6+8}{2} =1 \\ \\ x_{2} = \frac{-6-8}{2} =-7$
Answer: x₁ = 1
   x₂ = - 7

№18
$2 x^{2} -3x+4=3 \\ 2 x^{2} -3x+4-3=0 \\ 2 x^{2} -3x+1=0 \\ \\ D= -3 ^{2} -4*2=9-8=1 \\ \\ x_{1} = \frac{3+1}{2*2} = \frac{4}{4} =1 \\ \\ x_{2} = \frac{3-1}{2*2} = \frac{2}{4} =0.5$
Answer: x₁ = 1
     x₂ = 0,5.

№19
$2 x^{2} -4x-5=0 \\ D=-4 ^{2} -4*2*(-5)=16+40=56 \\ \\ x_{1}= \frac{4+ \sqrt{56} }{2*2} = \frac{4}{4} + \sqrt{ \frac{56}{16} } =1+ \sqrt{3.5} \\ \\ x_{2} = \frac{4- \sqrt{56} }{2*2} = \frac{4}{4} - \sqrt{ \frac{56}{16} } =1- \sqrt{3.5} 
$
Answer: x₁ = 1 + √3.5
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4 years ago

Which angles are complementary to each other?

jonny [76]

Answer:

<1 and <2

Step-by-step explanation:

Complementary angles are two angles which their measure add up to 90 degrees.

There are only one angle pair that meet this requirement:

angle 2 and angle 1

8 0

2 years ago

Mr. McGregor went to Target to buy four pairs of dress socks. There was a 30% off sale on the socks, and his total bill before t

Lena [83]

Answer:

Each pair of socks cost $4.55

Step-by-step explanation:

14*.30=4.2

14+4.2=18.2

18.2/4= 4.55

4 0

3 years ago

Read 2 more answers