All categories

3 years ago

Find the value of "k", given that one solution of the equation x2-kx+21=0 is 3

Mathematics

1 answer:

Ilia_Sergeevich [38]3 years ago

5 0

Plug in 3 for x and solve for k.
(3)^2-3k+21=0
3k=9+21
3k=30
k=10

You might be interested in

For Thanksgiving Break Nykouth and her family is going to visit relatives in Nebraska. Her dad has found a hotel room at the Hil

taurus [48]

Answer:

109n + 35

Step-by-step explanation:

I'm not sure what you are asking because you have no question in there

8 0

2 years ago

Help? pls? (10 points) (image down below to make it easier to understand.)

dusya [7]

This is middle school??? AinT no way

7 0

2 years ago

Read 2 more answers

5x-11=3x+5 solve for ”x”

I am Lyosha [343]

Answer:

x = 8

Step-by-step explanation:

Step 1: Write equation

5x - 11 = 3x + 5

Step 2: Solve for x

Subtract 3x on both sides: 2x - 11 = 5

Add 11 to both sides: 2x = 16

Divide both sides by 2: x = 8

Step 3: Check

Plug in x to verify it is a solution.

5(8) - 11 = 3(8) + 5

40 - 11 = 24 + 5

29 = 29

4 0

3 years ago

A right circular cone is undergoing a transformation in such a way that the radius of the cone is increasing at a rate of 1/2 in

Ivenika [448]

Answer:

The volume is decreasing at the rate of 1.396 cubic inches per minute

Step-by-step explanation:

Given

Shape: Cone

$\frac{dr}{dt} =\frac{1}{2}$ --- rate of the radius

$\frac{dh}{dt} =-\frac{1}{3}$ --- rate of the height

$r = 2$

$h = \frac{1}{3}$

Required

Determine the rate of change of the cone volume

The volume of a cone is:

$V = \frac{\pi}{3}r^2h$

Differentiate with respect to time (t)

$\frac{dV}{dt} = \frac{\pi}{3}(2rh \frac{dr}{dt} + r^2 \frac{dh}{dt})$

Substitute values for the known variables

$\frac{dV}{dt} = \frac{\pi}{3}(2*2*\frac{1}{3}* \frac{1}{2} - 2^2 *\frac{1}{3})$

$\frac{dV}{dt} = \frac{\pi}{3}(\frac{4}{3}* \frac{1}{2} - \frac{4}{3})$

$\frac{dV}{dt} = \frac{\pi}{3}(\frac{4}{3}(\frac{1}{2} - 1))$

$\frac{dV}{dt} = \frac{\pi}{3}(\frac{4}{3}*- 1)$

$\frac{dV}{dt} = -\frac{\pi}{3}*\frac{4}{3}$

$\frac{dV}{dt} = -\frac{22}{7*3}*\frac{4}{3}$

$\frac{dV}{dt} = -\frac{22}{21}*\frac{4}{3}$

$\frac{dV}{dt} = -\frac{88}{63}$

$\frac{dV}{dt} =-1.396in^3/min$

The volume is decreasing at the rate of 1.396 cubic inches per minute

3 0

3 years ago

Make 'm' the subject of the formula'k=3m-2

zaharov [31]

Answer:

$m = \frac{k + 2}{3}$

Step-by-step explanation:

$k = 3m - 2 \\ 3m = k + 2 \\ m = \frac{k + 2}{3}$

4 0

3 years ago

Read 2 more answers