Exercice 2:

To increase or decrease an amount by 30% what single multiplier would you use?

Nataly_w [17]

100%-30%=70%
100%+30%=130%

to decrese by 30%, multiply by 70%
to increase by 30%, multiply by 130%

5 0

2 years ago

Read 2 more answers

What is b1 and r of geometrical sequence if b3 −b1 = 16 and b5 −b3 = 144.

Naily [24]

Answer:

b1 = 2 ; r = 3

Step-by-step explanation:

Given that :

if b3 −b1 = 16 and b5 −b3 = 144.

For a geometric series :

Ist term = a

Second term = ar

3rd term = ar^2

4th term = ar^3

5th term = ar^4 ;...

If b3 - b1 = 16;

ar^2 - a = 16

a(r^2 - 1) = 16 - - - (1)

b5 - b3 = 144

ar^4 - ar^2 = 144

ar^2(r^2 - 1) = 144 - - - - (2)

Divide (1) by (2)

a(r^2 - 1) / ar^2(r^2 - 1) = 16 /144

a / ar^2 = 1 / 9

ar^2 = 9a

Substitute for a in ar^2 - a = 16

9a - a = 16

8a = 16

a = 2

From ar^2 - a = 16

2r^2 - 2 = 16

2r^2 = 16 + 2

2r^2 = 18

r^2 = 18 / 2

r^2 = 9

r = √9

r = 3

Hence ;

a = b1 = 2 ; r = 3

7 0

3 years ago

3 + x = 9 solve for x

Lerok [7]

X is equal to 6
3+6=9
X=6

4 0

2 years ago

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What is the equation of the following line written in slope-intercept form -2/3 and -1/-4? y = -11x - 7 y = -7x + 11 y = -7x - 1

Snowcat [4.5K]

Answer:

$y=-7x-11$

Step-by-step explanation:

Given:

The two points on the line are $(-2,3)$ and $(-1,-4)$ .

The slope of the line joining two points $(x_{1},y_{1})$ and $(x_{2},y_{2})$ is given as:

$Slope,m=\frac{y_{2}-y_{1}}{x_{2}-x_{1}}$

Here, $x_{1}=-2,y_{1}=3,x_{2}=-1,y_{2}=-4$

∴ $m=\frac{-3-4}{-1-(-2)}=\frac{-7}{-1+2}=\frac{-7}{1}=-7$

Equation of line with a point $(x_{1},y_{1})$ and slope $m$ is given as:

$y-y_{1}=m(x-x_{1})$

Plug in -2 for $x_{1}$ , 3 for $y_{1}$ and -7 for $m$ . This gives,

$y-3=-7(x-(-2))\\y-3=-7(x+2)\\y-3=-7x-(7\times 2)\\y-3=-7x-14\\y=-7x-14+3\\y=-7x-11$

Therefore, the equation of the line in vertex form is $y=-7x-11$ .

4 0

2 years ago

Verify that your point from Question 2 is a solution to 2x-y=-12x−y=−1 AND is also a solution to y=5x-5y=5x−5. What does it mean

Vera_Pavlovna [14]

Answer:

(a) Verified

(b) They are simultaneous equations

Step-by-step explanation:

Given

$2x - y = -1$

$y =5x - 5$

Required

Verify that: $(x,y) = (2,5)$ is a solution

We have:

$2x - y = -1$

Substitute: $(x,y) = (2,5)$

$2 * 2 - 5 = -1$

Evaluate all products

$4 - 5 = -1$

Subtract:

$-1 = -1$

Because both sides of the equation are equal, then the point is a solution

Also: $y =5x - 5$

Substitute: $(x,y) = (2,5)$

$5 = 5 * 2 - 5$

Evaluate all products

$5 = 10 - 5$

Subtract:

$5 = 5$

Because both sides of the equation are equal, then the point is a solution

Because the given point is a solution to both equations, then they are simultaneous equation

7 0

2 years ago