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3 years ago

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Four years ago, Jane was twice as old as Sam. Four years on from now, Sam will be 3/4 of Jane's age. How old is Jane now?

2 answers:

Sever21 [200]3 years ago

8 0

How old is sam? We need that first

Genrish500 [490]3 years ago

5 0

12 is Jane's Age now. 8 is Jame's age now

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kherson [118]

Answer:

Point N(4, 1)

General Formulas and Concepts:

<u>Pre-Algebra</u>

Order of Operations: BPEMDAS

Brackets
Parenthesis
Exponents
Multiplication
Division
Addition
Subtraction

Left to Right

Equality Properties

Multiplication Property of Equality
Division Property of Equality
Addition Property of Equality
Subtraction Property of Equality<u> </u>

<u>Algebra I</u>

Coordinates (x, y)
Functions
Function Notation
Terms/Coefficients
Anything to the 0th power is 1
Exponential Rule [Rewrite]: $\displaystyle b^{-m} = \frac{1}{b^m}$
Exponential Rule [Root Rewrite]: $\displaystyle \sqrt[n]{x} = x^{\frac{1}{n}}$

<u>Calculus</u>

Derivatives

Derivative Notation

Derivative of a constant is 0

Basic Power Rule:

f(x) = cxⁿ
f’(x) = c·nxⁿ⁻¹

Derivative Rule [Chain Rule]: $\displaystyle \frac{d}{dx}[f(g(x))] =f'(g(x)) \cdot g'(x)$

Step-by-step explanation:

<u>Step 1: Define</u>

<u /> $\displaystyle y = \sqrt{x - 3}$ <u />

<u /> $\displaystyle y' = \frac{1}{2}$ <u />

<u />

<u>Step 2: Differentiate</u>

[Function] Rewrite [Exponential Rule - Root Rewrite]: $\displaystyle y = (x - 3)^{\frac{1}{2}}$
Chain Rule: $\displaystyle y' = \frac{d}{dx}[(x - 3)^{\frac{1}{2}}] \cdot \frac{d}{dx}[x - 3]$
Basic Power Rule: $\displaystyle y' = \frac{1}{2}(x - 3)^{\frac{1}{2} - 1} \cdot (1 \cdot x^{1 - 1} - 0)$
Simplify: $\displaystyle y' = \frac{1}{2}(x - 3)^{-\frac{1}{2}} \cdot 1$
Multiply: $\displaystyle y' = \frac{1}{2}(x - 3)^{-\frac{1}{2}}$
[Derivative] Rewrite [Exponential Rule - Rewrite]: $\displaystyle y' = \frac{1}{2(x - 3)^{\frac{1}{2}}}$
[Derivative] Rewrite [Exponential Rule - Root Rewrite]: $\displaystyle y' = \frac{1}{2\sqrt{x - 3}}$

<u>Step 3: Solve</u>

<em>Find coordinates</em>

<em />

<em>x-coordinate</em>

Substitute in <em>y'</em> [Derivative]: $\displaystyle \frac{1}{2} = \frac{1}{2\sqrt{x - 3}}$
[Multiplication Property of Equality] Multiply 2 on both sides: $\displaystyle 1 = \frac{1}{\sqrt{x - 3}}$
[Multiplication Property of Equality] Multiply √(x - 3) on both sides: $\displaystyle \sqrt{x - 3} = 1$
[Equality Property] Square both sides: $\displaystyle x - 3 = 1$
[Addition Property of Equality] Add 3 on both sides: $\displaystyle x = 4$

<em>y-coordinate</em>

Substitute in <em>x</em> [Function]: $\displaystyle y = \sqrt{4 - 3}$
[√Radical] Subtract: $\displaystyle y = \sqrt{1}$
[√Radical] Evaluate: $\displaystyle y = 1$

∴ Coordinates of Point N is (4, 1).

Topic: AP Calculus AB/BC (Calculus I/II)

Unit: Derivatives

Book: College Calculus 10e

4 0

2 years ago

Old Navy has a sale on $15 shirts: buy 3

UNO [17]

The amount that the would be paid after 40% discount is $27

<h3>Word Problem</h3>

Given Data

Cost of a shirt = $15

Discount = 40%

Let us find the cost of three shirt

= 15*3

= $45

Let us find 40% discount of $45

= 40/100*45

= 0.4*45

= $18

Let us find the amount after discount

= 45-18

= $27

Learn more about word problem here:

brainly.com/question/25693822

7 0

2 years ago

When rock layers are bent, a ____________is created.

DedPeter [7]

(a.) is the answr. ............................................

4 0

3 years ago

Read 2 more answers

It is given 5 and h + 1 are the roots of the quadratic equation x² + (k - 1)x - 5 = 0,where h and k are constant.Find the value

Liono4ka [1.6K]

Answer:

Hello,

<u>k=-3 and h=-2</u>

Step-by-step explanation:

$5\ is\ a \ root \of \ x^2+(k-1)*x-5=0\\\\5^2+(k-1)*5-5=0\\\\5*(k-1)+20=0\\\\k-1=\dfrac{-20}{5} \\\\k=-4+1\\\\\boxed{k=-3}\\$

h+1 is thus a root of x²+(-3-1)*x-5=0

x²-4x-5=0

x²+x-5x-5=0

x(x+1)-5(x+1)=0

(x+1)(x-5)=0

h+1=-1

<u>h=-2</u>

6 0

3 years ago

Write the equation of the line that passes through the points (-8,-5) (5,−8)

Nikolay [14]

Answer:

y=-3/13x-89/13

Step-by-step explanation:

m=y²-y¹/x²-x¹

m=(-8)-(-5)/5-(-8)

m=-3/13

y-y=m(x-x1)

y-(-8)=-3/13(x-5)

y+8= -3/13x+15/13

-8 -8

y=-3/13x-89/13

7 0

3 years ago