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3 years ago

PLEASE HELP I JUST NEED TO KNOW HOW TO DO IT

Mathematics

2 answers:

RoseWind [281]3 years ago

7 0

Your answer should be x=7 and y=7

Brilliant_brown [7]3 years ago

5 0

Answer:

y=7, x=7

Step-by-step explanation:

They both equal y, so you can set the right part of the equations equal to each other

4x-21=2x-7

solve for x

2x-21=-7

2x=14

x=7

knowing x, we can now substitute back into one of the original equations to find y

y=4(7)-21=28-21=7

y=2(7)-7=14-7=7

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The cost of a peanut butter bar is $0.07 more than the cost of a chocolate bar. If you buy 5 peanut butter bars and 6 chocolate

Licemer1 [7]

Hello!

To be quick and simple, your answer would be $0.55

4 0

3 years ago

What is the explict rule for the sequence 12,22,32,42

icang [17]

The explicit rule for given sequence is:

$a_n=2+10n$

Further explanation:

We have to determine first of all if the sequence is arithmetic or geometric.

If the difference of two consecutive terms is same then the sequence is arithmetic sequence
If the ratio of two consecutive terms is same then the sequence is geometric sequence

Given sequence is:

12,22,32,42

$a_1=12\\a_2=22\\a_3=32\\.......\\Let\\d=Common\ difference\\d=a_2-a_1=22-12=10\\d=a_3-a_2=32-22=10$

The common difference is 10 which is same for all consecutive terms. So the sequence is an arithmetic sequence.

The general formula for arithmetic sequence is:

$a_n=a_1+(n-1)d\\Here,\\a_n\ is\ the\ nth\ term\\a_1\ is\ the\ first\ term\\d\ is\ the\ common\ difference$

Putting the values of a1 and d

$a_n= 12+(n-1)(10)\\a_n=12+10n-10\\a_n=2+10n$

The explicit rule for given sequence is:

$a_n=2+10n$

Keywords: Arithmetic sequence, Common Difference

Learn more about arithmetic sequence at:

#LearnwithBrainly

8 0

3 years ago

A boat travels 12 km upstream and back in 1 hour 45 minutes. If the speed of the current is 3 km/h throughout, find the speed of

Elza [17]

Answer:

14.3 km/h to 3 significant figures

Step-by-step explanation:

Let time travelling upstream be t1 hours and downstream = t2 hours.

t1 + t2 = 1.75..........................(1)

Let v be the speed of the boat in still water.

12 / t1 = v - 3.........................(2)

12 / t2 = v + 3........................(3)

From (1) and (3) , substituting for t2:-

12 / (1.75 - t1) = v + 3 ..................(4)

Subtract:- (2) - (4):-

12 / t1 - 12 / (1.75 - t1) = -6

12(1 .75 - t1) - 12t1 = -6t1(1.75 - t1)

21 - 12t1 - 12t1 = -10.5t1 + 6t^2

6t1^2 + 13.5t1 - 21 = 0

Solving this gives t1 = 1.058 hours

Therefore the speed in still water (v) = 12/1.058 + 3 = 14.3 to 3 sig figs

3 0

3 years ago

Select all the expressions below which represent a 20% discount off the price of an item that originally costs d dollars.

Hoochie [10]

B. d - 0.2

20%= 20/100= 0.2

so price= d-0.2

8 0

3 years ago

Lease help me please thanks you

o-na [289]

Answer:

x=6

Step-by-step explanation:

8 0

2 years ago