Question

(11) 5 pencils and 7 pens together cost * 50, whereas 7 pencils and 5 pens togethe
cost 46. Find the cost of one pencil and that of one pen. geometrically ​

Answer 1

Answer:

Step-by-step explanation:

Let pens be P and pencils be p

5p + 7P = 50 ----------1

7p + 5P = 46------------2

Using substitution method,

5p + 7P = 50

5p = 50 - 7p

p = $\frac{50-7P}{5}$  ----------------3

Insert equation 3 in equation 2

7$(\frac{50-7P}{5} )$ + 5P = 46

$\frac{7(50-7P)}{5}$ + 5P = 46

$\frac{350-49P}{5}$ + 5P = 46

Multiply each term by 5

$\frac{350-49P}{5} * \frac{5}{1}$  + (5P x 5) = 46 x 5

350 - 49P + 25P = 230

Collect like terms

-49P + 25P = 230 - 350

-24P = -120

Divide both sides by -24

P = 5

Insert P in equation 3 to get p

p = $\frac{50-7(5)}{5}$

p = $\frac{50-35}{5}$

p = 15/5

p=3

Hence, 1 pen costs 5 while the pencil costs 3

Answer 2

Answer:

can't describe

Step-by-step explanation:

answer is. one pen costs 5 while the pencil costs 3