All categories

3 years ago

8x + 7y = 89 2x + 5y = 45

Mathematics

2 answers:

Naddik [55]3 years ago

5 0

Answer:

(5,7)

Step-by-step explanation:

8x + 7y = 89

2x + 5y = 45

Multiply the second equation by 4

4(2x + 5y) = 45*4

8x +20y = 180

Subtract the first equation

8x +20y = 180

-8x -7y = -89

--------------------------

13y = 91

Divide each side by 13

13y/13 = 91/13

y =7

Now solve for x

2x+5y =45

2(x) +5(7) = 45

2x +35 = 45

Subtract 35 from each side

2x+35-35 = 45-35

2x =10

Divide each side by 2

2x/2 = 10/2

x=5

kkurt [141]3 years ago

5 0

Answer:

x=1.00,y=11.38

Step-by-step explanation:

This is simultaneous equation,we can solve by using elimination method

8x+7y=89..(1)

2x+5y=45...(2)

Multiply (1) by 2

16x+14y=178...(3)

Multiply (2) by 8

16y+40y=360...(4)

Substrate (3) from (4)

26y=182

Divide both sides by 26

y=11.38

Substitute the value of y into (1)

8x+7(11.38)=89

8x+79.625=89

8x=89-79.625

8x=9.375

Divide both sides by 8

x=1.00

Therefore x=1.00, y=11.38

You might be interested in

Select the correct answer.

juin [17]

Answer:

Step-by-step explanation:

$\sqrt{x} + 3 = 12 \\ \\ \sqrt{x} = 12 - 3 \\ \\ \sqrt{x} = 9 \\ \\ {( \sqrt{x} )}^{2} = {(9)}^{2} \\ \\ x = 81$

7 0

2 years ago

Ashley needs to buy some pencils. Brand A has 20 pencils for $6. Brand B has 40 pencils for $8.50. Based on the unit price, whic

Kruka [31]

Answer:

The answer to your question is Brand B

Step-by-step explanation:

Data

Brand A amount of 20 pencils cost $6

Brand B amount of 40 pencils cost $8.5

Process

1.- Calculate the unit price of each brand of pencils dividing the cost by the number of pencils

Brand A 6/20 = $0.3

Brand B 8.5/40 = $0.21

2.- Conclusion

Brand B is a better deal because you buy more pencils for a lower price.

3 0

3 years ago

A digit in the hundredths place has ten times the value of the same digit in the thousands place

bagirrra123 [75]

That is true very good

5 0

3 years ago

Keenan will run 2.5 miles from his house to Jared’s house. He plans to hang out for 45 minutes before walking home. If he can ru

jenyasd209 [6]

Answer:

Kennan will be from home approximately an hour and 48 minutes.

Step-by-step explanation:

We must know that total time ( $t_{T}$ ) that Keenan will be from home is the sum of run ( $t_{R}$ ), hang out ( $t_{H}$ ) and walk times ( $t_{W}$ ), measured in hours:

$t_{T} = t_{R}+t_{H}+t_{W}$

If Keenan runs and walks at constant speed, then equation above can be expanded:

$t_{T} = \frac{x_{R}}{v_{R}}+t_{H}+ \frac{x_{W}}{v_{W}}$

Where:

$x_{R}$ , $x_{W}$ - Run and walk distances, measured in miles.

$v_{R}$ , $v_{W}$ - Run and walk speeds, measured in miles per hour.

Given that $x_{R}=x_{W} = 2.5\,mi$ , $v_{R} = 6\,\frac{mi}{h}$ , $v_{W} = 4\,\frac{mi}{h}$ and $t_{H} = 0.75\,h$ , the total time is:

$t_{T} = \frac{2.5\,mi}{6\,\frac{mi}{h} } + 0.75\,h+\frac{2.5\,mi}{4\,\frac{mi}{h} }$

$t_{T} = 1.792\,h$ ( $1\,h\,48\,m$ )

Kennan will be from home approximately an hour and 48 minutes.

7 0

3 years ago

What is the value of |−25|?

Kisachek [45]

The answer is 25.

Explanation: absolute value is always the opposite of the number inside the bars unless if the number is already positive, absolute value is always positive.

5 0

3 years ago

Read 2 more answers