ASAP PLEASE HELP!! WILL GIVE BRAINEST!!! what is the value of x and y

F(x) = {4x² – 1, x = -2 x > -2 la -x, what is f(0)

beks73 [17]

Yes that answer is accurate

5 0

3 years ago

Write the system in a matrix equation. Then, find the determinant of the matrix containing the coefficients.

Shtirlitz [24]

Answer:

See below for the matrix

D = 100

Step-by-step explanation:

$\left[\begin{array}{cccc}3&2&1&-8\\-1&-2&4&7\\1&-6&-3&15\end{array}\right]$

3 2 1

D = -1 -2 4 = 3(-2)(-3) + 2(4)(1) + 1(-1)(-6)

1 -6 -3

- 1(-2)(1) - 3(4)(-6) - 2(-1)(-3)

= 18 + 8 + 6 + 2 + 72 - 6

= 100

Sorry, I can't type the vertical bars.

I hope this is what you are looking for.

5 0

3 years ago

Lily swims for 5 hours in stream that has a current of 1 mph. She leaves her dock, swims upstream for 2 miles and then swim back

antiseptic1488 [7]

Answer:

Swimming speed in still water is approximately 1.5 mph

Step-by-step explanation:

Given the speed of the current = 1 mph

distance she swims upstream =2 miles,

the total time = 5 hours.

She swam 2 miles upstream against the current and 2 miles back to the dock with the current. The formula that relates distance, time, and rate is $d = r t\ \ \ \ or \ \ \ t= \frac{d}{r}$

Let x be the speed in still water.

Then her speed with the current is x + 1, and

her speed against the current is x – 1.

Total time is equal to 2 miles with upstream and 2 miles downstream.

$\frac{2}{x+1}+\frac{2}{x-1}=5\\\\\frac{2(x-1)}{(x+1)(x-1)}+\frac{2(x+1)}{(x-1)(x+1)}=5\\\\\frac{2x-2}{(x^2-1)}+\frac{2x+2)}{(x^2-1)}=5\\\\\frac{2x-2+2x+2)}{(x^2-1)}=5\\\\4x=5(x^2-1)\\4x= 5x^2-5\\0= 5x^2-4x-5$

Now Using quadratic formula to solve above equation we get;

$x= \frac{-b \±\sqrt{b^2-4ac}} {2a}\\\\here \ \ a= 5,b=-4,c=-5\\\\x= \frac{-(-4) \±\sqrt{(-4)^2-4\times 5\times-5}} {2\times5}\\\\x=\frac{4 \±\sqrt{16+100}} {10}\\\\x=\frac{4 \±\sqrt{116}} {10}=x=\frac{4 \±2\sqrt{29}} {10}= x=\frac{2 \±\sqrt{29}} {5}\\ x \approx 1.5 \ or \ x = -0.7$

Since speed must be positive, Hence speed of still water is about 1.5 miles per hour.

3 0

3 years ago

PLEASEE HELPPP! what is the measure of

Debora [2.8K]

Answer:

x=12

Step-by-step explanation:

Im not sure which measure you're talking about, but I'll show you what I did here:

A triangle = 180 degrees.

4x + 8x + 4x =16x

-8 - 1 - 3 = -12

180 = 16x - 12 -Add 12 to both sides

192 = 16x -divide by 16 to get x by itself

12 = x

Angle A = 88 degrees (8 times 12 then subtract 8)

Angle B = 47 degrees (4 times 12 then subtract 1)

Angle C = 45 degrees (4 times 12 then subtract 3)

5 0

2 years ago

Find the nth terms of the following Ap 100, 91, 82

Rom4ik [11]

Answer:

The nth term is 109-9n

Step-by-step explanation:

Here, we want to find the nth term of the given arithmetic sequence

Mathematically, we have the nth term as;

Tn = a + (n-1)d

where a is the first term which is 100 in this case

d is the common difference which is the value obtained by subtracting the preceding term from the succeeding term; it is constant throughout the sequence

The value here is thus;

82-91 = 91-100 = -9

Substituting these values

Tn = 100 + (n-1)-9

Tn = 100 -9n + 9

Tn = 100 + 9 - 9n

Tn = 109-9n

6 0

3 years ago