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3 years ago

What value of r makes this equation true? justify your solution. 0.4r - 7 = -.3r +2.8

Mathematics

2 answers:

Georgia [21]3 years ago

6 0

Answer:

all work is pictured and shown

fiasKO [112]3 years ago

3 0

The answer is 14

0.4r-7=-.3r+2.8

Add 7 to both sides. -7+7=0 so it cancels on the left. 2.8+7=9.8.

0.4r=-.3r+9.8.

Add .3r to both sides. -.3r+3r=0 so it cancels on the right. 0.4r+.3r=0.7r.

0.7r=9.8

Divide 0.7 to both sides. 9.8 divided by 0.7 = 14

So r=14

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which function has an inverse that is a function? a. b(x) = x2 3 b. d(x) = –9 c. m(x) = –7x d. p(x) = |x|

andrew11 [14]

<span>m(x) = –7x has an inverse which is a function.</span>

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2 years ago

Complete the equation of the line through (-9,-9) and (-6,0)

Rudik [331]

For this case we have that by definition, the equation of the line of the slope-intersection form is given by:

$y = mx + b$

Where:

m: It is the slope of the line

b: It is the cut-off point with the y axis.

According to the data of the statement we have the following points:

$(x_ {1}, y_ {1}): (- 9, -9)\\(x_ {2}, y_ {2}): (- 6,0)$

We found the slope:

$m = \frac {y_ {2} -y_ {1}} {x_ {2} -x_ {1}} = \frac {0 - (- 9)} {- 6 - (- 9)} = \frac { 9} {- 6 + 9} = \frac {9} {3} = 3$

Thus, the equation is of the form:

$y = 3x + b$

We substitute one of the points and find b:

$0 = 3 (-6) + b\\0 = -18 + b\\b = 18$

Finally, the equation is:

$y = 3x + 18$

Answer:

$y = 3x + 18$

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3 years ago

Your friend owes her parents $100. She saves $25 every two weeks. Write an equation That illustrates this situation.

Nutka1998 [239]

If you divide 100 by 25 you will get 4. Then you multiply 4 and 2, which will get you 8. So, it will take her 8 weeks to pay her parents.

7 0

2 years ago

K - 263.48 = 381.09 solve this equation

Sedbober [7]

K-263.48=381.09
we add 263.48 on both sides
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3 years ago

Read 2 more answers

Please help with math problem?

Hoochie [10]

Answer:

KM=41.6

Step-by-step explanation:

$\frac{HJ}{IJ} =\frac{KM}{ML} \\\frac{8}{6} =\frac{KM}{31.2} \\$

Cross Multiply and Solve for KM.

$6*KM=8*31.2\\KM=\frac{8*31.2}{6} \\KM=41.6$

5 0

1 year ago