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3 years ago

When x = 5, the value of the expression –2(x – 10) is

Mathematics

1 answer:

Nikitich [7]3 years ago

7 0

Ten subtracted from five is negative five.Negative five multiplied by negative two is ten

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2 x + 5 = 27 solve for x

Mnenie [13.5K]

Answer:

x=11

Step-by-step explanation:

2x+5=27

Subtract 5 on both side of 27

You will get 2x=22

Then divide it by 2

You will get x=11

8 0

4 years ago

Read 2 more answers

Use the discriminant to determine what type of roots the equations will have, and categorize the equations according to their ro

topjm [15]

Step-by-step explanation:

The discriminant of the quadratic equation $ax^2+bx+c=0$ :

$\Delta=b^2-4ac$

If Δ < 0, then the equation has two complex roots $x=\dfrac{-b\pm\sqrt\Delta}{2a}$

If Δ = 0, then the equation has one repeated root $x=\dfrac{-b}{2a}[/tex If Δ > 0, then the equation has two discint roots [tex]x=\dfrac{-b\pm\sqrt\Delta}{2a}$

$1.\ x^2-4x+2=0\\\\a=1,\ b=-4,\ c=2\\\\\Delta=(-4)^2-4(1)(2)=16-8=8>0,\ \bold{two\ distinct\ roots}\\\sqrt\Delta=\sqrt8=\sqrt{4\cdot2}=2\sqrt2\\\\x=\dfrac{-(-4)\pm2\sqrt2}{2(1)}=\dfrac{4\pm2\sqrt2}{2}=2\pm\sqrt2\\\\==============================\\\\2.\ 5x^2-2x+3=0\\\\a=5,\ b=-2,\ c=3\\\\\Delta=(-2)^2-4(5)(3)=4-60=-56$

$3.\ 2x^2+x-6=0\\\\a=2,\ b=1,\ c=-6\\\\\Delta=1^2-4(2)(-6)=1+48=49>0,\ \bold{two\ distinct\ roots}\\\sqrt\Delta=\sqrt{49}=7\\\\x=\dfrac{-1\pm7}{(2)(2)}\\\\x_1=\dfrac{-8}{4}=-2,\ x_2=\dfrac{6}{4}=\dfrac{3}{2}\\\\==============================\\\\4.\ 13x^2-4=0\qquad\text{add 4 to both sides}\\\\13x^2=4\qquad\text{divide both sides by 13}\\\\x^2=\dfrac{4}{13}\to x=\pm\sqrt{\dfrac{4}{13}},\ \bold{two\ distinct\ roots}\\\\==============================$

$5.\ x^2-6x+16=0\\\\a=1,\ b=-6,\ c=16\\\\\Delta=(-6)^2-4(1)(16)=36-64=-28$

$7.\ 4x^2+11=0\qquad\text{subtract 11 from both sides}\\\\4x^2=-11\qquad\text{divide both sides by 4}\\\\x^2=-\dfrac{11}{4}\to x=\pm\sqrt{-\dfrac{11}{4}}\\\\x=\pm\dfrac{\sqrt{11}}{2}\ i,\ \bold{two\ complex\ roots}$

6 0

3 years ago

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Haben knows that the angle of elevation from the top of a rock formation to a stake in the ground 50 feet from its base is 42°.

Murrr4er [49]

Answer:

The height of the rock formation is $45.02\ ft$

Step-by-step explanation:

see the attached figure to better understand the problem

we know that

$tan(42\°)=h/50$

solve for h

$h=50*tan(42\°)=45.02\ ft$

4 0

4 years ago

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Which phrase describes a nonlinear function?

Lorico [155]

The only non-linear equation from your choices is the area of a circle as it is:

A=πr^2 and if you take the derivative of A you have:

dA/dr=2πr

So the rate of change changes as r changes, it is not constant thus the function has acceleration, so velocity changes.

This is in contrast to any linear equation which is of the form:

y=mx+b now taking the derivative you see that:

dy/dx=m, now m is a constant value, which means that there is no acceleration and the velocity remains constant.

5 0

3 years ago

High temperatures were recorded for 30 consecutive days: 50, 45, 49, 50, 43, 49, 50, 49, 45, 49, 47, 47, 44, 51, 51, 44, 47, 46,

Simora [160]

The answer is 21, you subtract the smallest number (30) by the biggest number (51)

7 0

2 years ago

Read 2 more answers