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2 years ago

10a-5+3a-2a when a=7

Mathematics

1 answer:

cestrela7 [59]2 years ago

6 0

72 is the correct answer.

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How do I solve |5-3p|+9=13p+8

anastassius [24]

Answer:

p = -2/5 or 3/8

Step-by-step explanation:

|5 − 3p| + 9 = 13p + 8

|5 − 3p| = 13p − 1

If 5 − 3p is positive:

5 − 3p = 13p − 1

6 = 16p

p = 3/8

If 5 − 3p is negative:

-(5 − 3p) = 13p − 1

-5 + 3p = 13p − 1

-4 = 10p

p = -2/5

Alternatively, we can square both sides of the equation:

(5 − 3p)² = (13p − 1)²

25 − 30p + 9p² = 169p² − 26p + 1

0 = 160p² + 4p − 24

0 = 40p² + p − 6

0 = (5p + 2) (8p − 3)

p = -2/5 or 3/8

8 0

2 years ago

Which plot has an outlier?

inna [77]

Answer:

girls

Step-by-step explanation:

an outlier is a number that is greater than the others.

boys doesnt have and outlier because the highest number has other numbers near it, while girls doesn't.

5 0

2 years ago

A tank initially contains 60 gallons of brine, with 30 pounds of salt in solution. Pure water runs into the tank at 3 gallons pe

adoni [48]

Answer:

the amount of time until 23 pounds of salt remain in the tank is 0.088 minutes.

Step-by-step explanation:

The variation of the concentration of salt can be expressed as:

$\frac{dC}{dt}=Ci*Qi-Co*Qo$

being

C1: the concentration of salt in the inflow

Qi: the flow entering the tank

C2: the concentration leaving the tank (the same concentration that is in every part of the tank at that moment)

Qo: the flow going out of the tank.

With no salt in the inflow (C1=0), the equation can be reduced to

$\frac{dC}{dt}=-Co*Qo$

Rearranging the equation, it becomes

$\frac{dC}{C}=-Qo*dt$

Integrating both sides

$\int\frac{dC}{C}=\int-Qo*dt\\ln(\abs{C})+x1=-Qo*t+x2\\ln(\abs{C})=-Qo*t+x\\C=exp^{-Qo*t+x}$

It is known that the concentration at t=0 is 30 pounds in 60 gallons, so C(0) is 0.5 pounds/gallon.

$C(0)=exp^{-Qo*0+x}=0.5\\exp^{x} =0.5\\x=ln(0.5)=-0.693\\$

The final equation for the concentration of salt at any given time is

$C=exp^{-3*t-0.693}$

To answer how long it will be until there are 23 pounds of salt in the tank, we can use the last equation:

$C=exp^{-3*t-0.693}\\(23/60)=exp^{-3*t-0.693}\\ln(23/60)=-3*t-0.693\\t=-\frac{ln(23/60)+0.693}{3}=-\frac{-0.959+0.693}{3}= -\frac{-0.266}{3}=0.088$

5 0

2 years ago

A spinner with three congruent sections is spun with the results as shown. What is P(1)? 1 3 3 2 1 2 1 1 3 3 2 1 1 1 2 2 2 3 3 1

natima [27]

<span>Number of times that a spin comes up 1 divided by the total number of spins. P(1) = 8/21</span><span>

</span>

7 0

2 years ago

Read 2 more answers

A triangle has side lengths of 20 cm, 99 cm, and 108 cm. Classify it as acute, obtuse, or right.

vagabundo [1.1K]

Okay lets go down the list. It's not right since 20²+99²=10201 √10201=101 and you said a is wrong it's have to be B. obtuse

8 0

2 years ago