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4 Pencils and 2 rulers cost $8. 2 pencils and 4 rulers cost $10. Find the cost of 3 rulers and 3 pencils

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ArisingPlayerid

Answer:

$9

Step-by-step explanation:

Let, the price of pencils is x, and the price of rulers is y.

4x+2y=8.....(i)

2x+4y=10......(ii)

From eq(i),

2(2x+y)=8

2x+y=4

y=4-2x eq(iii)  .....put in eq(ii)

2x+4(4-2x)=10

2x+16-8x=10

-6x=10-16

x=-6/-6

x=1 put in eq (iii)

y=4-2(1)

y=2

Now, the price of 3 rulers and 3 pencils = 3x+3y=3(1)+3(2)

=9

Please give me brainlist.

Appshoterid
We can convert the statements into quadratic equations, which is not a big thing. In simple words, the equation which includes 2 unknowns. We can sustitute with x & y for the simplicity.

Let assume the price of pencil is x and the price of rulers is y. While doing the operations we can remove the units which is $ (for price).


So now we can rewrite the first statement as 4x + 2y = 8.
As everything is dividant of 2, I'm simplifying the eqution by dividing everything by 2.

So, 2x + y = 4 ----(1)

Similarly the second statement is, 2x+4y = 10.

So, 2x + 4y = 10 ----(2).

To solve this we need to make any of the variable (either x or y) zero. We can do that in multiple ways, Here I am trying to make the x =0 by substrating equation 1 from equation 2.

2x + 4y = 10 -
2x + y = 4
___________

-0 + 3y = 6

3y = 6

So y= 6/3=2

Now we have the value of y, to find x apply it in any eqution that has x

I'm applying it in eqution 2

2x + 2 = 4
2x = 2
x=1

Now we want to value the cost of 3 rulers and 3 pencils

3x + 3y = 3(1) + 3(2) = 3 + 6 = 9

So

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