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3 years ago

How can 9+3 =12 help you solve 12-9?

Mathematics

2 answers:

Dovator [93]3 years ago

7 0

9+3=12, 12-9=3, since those three numbers are in the first equation.

d1i1m1o1n [39]3 years ago

3 0

Well you know that 9+3=12 so you can reverse it and do 12-9=3 .Because 3 is the only one left in the equation of 9+3=12.

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This is for Algebra 2 and I need help ASAP! 22pts if you show work and explanation

elixir [45]

Answer:

Part 41) The solutions are 3 and 1

Part 42) The solution is 2 only

Step-by-step explanation:

Part 41) we have

$\left|5x-9\right|=x+3$

step 1

Find the first solution (case positive)

$+(5x-9)=x+3$

$5x-x=3+9$

$4x=12$

$x=3$

step 2

Find the second solution (case negative)

$-(5x-9)=x+3$

$-5x+9=x+3$

$5x+x=9-3$

$6x=6$

$x=1$

therefore

The negative case was resolved incorrectly

The solutions are 3 and 1

Part 42) we have

$\left|n-7\right|=3n-1$

step 1

Find the first solution (case positive)

$+(n-7)=3n-1$

$3n-n=-7+1$

$2n=-6$

$n=-3$

<em>Verify</em>

For n=-3

substitute

$\left|-3-7\right|=3(-3)-1$

$\left|-10\right|=-9-1$

$10=-10$ ------> is not true

therefore

$n=-3$ -------> is not a solution

step 2

Find the second solution (case negative)

$-(n-7)=3n-1$

$-n+7=3n-1$

$3n+n=7+1$

$4n=8$

$n=2$

therefore

The solution is 2

3 0

3 years ago

troy's truck has a 30 gallon gas tank and gets an average of 21 miles per gallon.write an equation to represent the amount of ga

GuDViN [60]

Let

x---------> represent the number of miles Troy's has driven

y--------> represent the amount of gas in Troy's truck

we know that

the equation that represents the amount of gas, y, in troy' s truck after driving a certain number of miles, x is

$y-y1=m*(x-x1)$

where

m is the slope---------> $\frac{gallon}{miles}$

in this problem the slope is equal to $-\frac{1}{21} \frac{gallons}{miles}$

it's negative because the tank is going to be consumed

assuming he starts with a full tank

$for\ x=0\ y=30\ gal$

substitute in the formula above

$y-y1=m*(x-x1)\\\\ y-30=-\frac{1}{21}*(x-0)\\\\ y=-\frac{x}{21}+30$

therefore

the answer is

the equation $y=-\frac{x}{21}+30$

8 0

3 years ago

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Two-thirds a number plus 4 is 7

Liono4ka [1.6K]

If you put <em>x</em> for "a number,"
2/3(x) + 4 = 7
2x/3 = 7-4
2x/3 = 3
x = 2

4 0

3 years ago

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Write the equation of the line if the slope = -3/5 and the line passes through (-4, 0). Show your work.

topjm [15]

Answer:

3x+5y+12=0

Step-by-step explanation:

This information is given in the question:

m=-3/5

x1=-4

y1=0

The formula for the equation of a line is:

y-y1=m (x-x1)

From this we can make a substitution

y-0=-3/5 (x--4)

Next simplify

y=-3/5 (x+4)

Multiply both sides of the equation by 5

5y=-3x-12

Make the right side of the equation equal to zero

3x+5y+12=0

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3 years ago

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Diano4ka-milaya [45]

Answer:

what grade

Step-by-step explanation:

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3 years ago