Question

If two pens and three pencils cost 86. Four pens and a pencil cost 112. How much does a pen cost?

Answer 1

cost of pen= x

cost of pencils=y

2x+3y=86.

4x+y=112.

solving

EQ 1× 2= 4x +6y=172

= 4x+y. =112

=(-). 5y= 60

y= 60/5

y=12.

substitute y=12 in eq1

2x+3y =86

2x+3×12 = 86

2x+ 36 = 86

2x = 86-36.d

2x=50

x=50/2

x=25.

cost of each pen = 25

Answer 2

Answer:

Step-by-step explanation

Let the cost of pen be x and cost of pencil be y

Then

2x+3y=86

4x+y=112

Solving equation 1

3y=86-2x

y=(86-2x)/3

Solving equation2

4x+y=112

y=112-4x

Now equating the results

(86-2x)/3=112-4x

85-2x=3(112-4x)

85-2x=336-12x

10x=250

x=25

Now y=112-4x

y=112-4(25)

y=112-100

y=12