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3 years ago

What's substitution for: X=y-7 X+8y=2

1 answer:

4 0

$\left \{ {{x=y-7} \atop {x+8y=2}} \right. \\\\
substitute\ x=y-7\ into \ the\ second\ equation\\\\
y-7+8y=2\\\\
9y-7=2\ \ \ | add\ 7\\\\
9y=9\ \ \ | divide\ by\ 9\\\\
y=1\\\\x=y-7=1-7=-6$

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A train traveled 210 miles in 3.5 hours to its first stop. It then continued on traveling another 130 miles in 2.5 hours. What w

valkas [14]

T = 6 [h]
s = 340 [mi]

v=s/t=340/6=56.7 [mi/h]
Answer C.

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4 years ago

Is this a funcion? Explain why. X: -2, 0, 1, -2 Y:4, 5, 4, 5

Alina [70]

Answer:

No

Step-by-step explanation:

it isn't a Function because the Domain (X coordinate) repeats a number.

Take this note:

Domain (x) repeats: Not a function

Domain(x) doesn't repeat: Function

Hope this helps ;)

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3 years ago

Read 2 more answers

Translate into an algebraic expression: n−1 increased by 110%

lorasvet [3.4K]

Answer:

Part 1) The algebraic expression is equal to $1.10(n-1)$ or $1.10n-1.10$

Part 2) The algebraic expression is equal to $\frac{1.10}{n}$

Step-by-step explanation:

Part 1) we have (n-1) increased by 110%

110%=110/100=1.10

The algebraic expression of (n-1) increased by 110% is equal to multiply 1.10 by (n-1)

$1.10(n-1)$

Distributed

$1.10n-1.10$

Part 2) we have n^(-1) increased by 110%

110%=110/100=1.10

The algebraic expression of n^(-1) increased by 110% is equal to multiply 1.10 by n^(-1)

Remember that

$n^{-1}=\frac{1}{n}$

$1.10(n^{-1})=1.10\frac{1}{n}=\frac{1.10}{n}$

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4 years ago

A shopkeeper buys a dress for $40

DanielleElmas [232]

Answer:

48 - 40 = $8, there is a $8 dollar increase.

Formula for change of percentage;

changed price

___________ x 100% (100/100)

original amount

Replace those values with the values we found;

40/48 x 100/100 = 20% increase.

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2 years ago

Find the gradient of the line Joining the points p(-2,6) and Q(3,-2)

Rudiy27

Answer:

$- \frac{8}{5}$

Step-by-step explanation:

$\boxed{gradient = \frac{y1 - y2}{x1 - x2} }$

(x₁, y₁) is the 1st coordinate while (x₂, y₂) is the 2nd coordinate.

Gradient of the line

$= \frac{6 - ( - 2)}{ - 2 - 3}$

$= \frac{6 + 2}{ - 5}$

$= - \frac{8}{5}$

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3 years ago