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3 years ago

Given f(x)=2x+1, find x if f(x)=17 Given f(x)=x+3, find x if f(x)=6

Mathematics

1 answer:

n200080 [17]3 years ago

4 0

X=8
X=3
Sorry if it’s wrong

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A positive real number is 2 less than another. When 4 times the larger is added to the square of the smaller, the result is 49.

Kobotan [32]

Answer:

The numbers are

$-2+3\sqrt{5}$ and $3\sqrt{5}$

Step-by-step explanation:

Let

x -----> the smaller positive real number

y -----> the larger positive real number

we know that

A positive real number is 2 less than another

$x=y-2$

$y=x+2$ ----> equation A

When 4 times the larger is added to the square of the smaller, the result is 49

$4y+x^2=49$ ----> equation B

substitute equation A in equation B

$4(x+2)+x^2=49$

solve for x

$x^2+4x-41=0$

The formula to solve a quadratic equation of the form

$ax^{2} +bx+c=0$

is equal to

$x=\frac{-b\pm\sqrt{b^{2}-4ac}} {2a}$

in this problem we have

$x^2+4x-41=0$

$a=1\\b=4\\c=-41$

substitute in the formula

$x=\frac{-4\pm\sqrt{4^{2}-4(1)(-41)}} {2(1)}$

$x=\frac{-4\pm\sqrt{180}} {2}$

$x=\frac{-4\pm6\sqrt{5}} {2}$

$x=-2\pm3\sqrt{5}$

The positive real number is

$x=-2+3\sqrt{5}$

Find the value of y

$y=x+2$

$y=-2+3\sqrt{5}+2$

$y=3\sqrt{5}$

6 0

4 years ago

What's the Error? 3+1(6+2) 4(6-2) 4(3) 12

gulaghasi [49]

Yes 12 thats the error

5 0

3 years ago

If f(x) = -2(5)*, what is f(2)?

Effectus [21]

Answer:

-2(5)^2

-2(25)

-50

Step-by-step explanation:

7 0

3 years ago

A rectangular soccer field is twice as long as it is wide. If the perimeter of a soccer field is 300 yards, what are the fields'

Masteriza [31]

A rectangular soccer field is twice as long as it is wide. If the perimeter of the soccer field is 300 yards , what are its dimensions?
I know the basic formula is 2W+2L=300 but i am not sure where to go from there...
-----
Equations:
2W + 2L = 300
L = 2W
----
Substitute for "L" and solve for "W":
2W + 2(2W) = 300
6W = 300
W = 50 yds (width)
----
Solve for "L":
L = 2W
L = 100 yds (length)
========================
Cheers.

8 0

3 years ago

HELPPP DOES ANYONE KNOW THE ANSWER???

IRISSAK [1]

Answer:

Step-by-step explanation:

solve equation.

5 0

2 years ago