Question

anyone mind helping me with this equation?

Answer 1

Let cost of an envelope = e

and cost of notebook paper = n

3e + 4n = 13.25 -------(1)

2e + 6n = 17 -----------(2)

From (1)

3e = 13.25 - 4n

e = 13.25 - 4n

3

substitute value of e in (2)

2(13.25 - 4n) + 6n = 17

3

26.5 - 8n + 6n = 17

3

26.5 - 8n + 18n = 17

3

26.5 + 10n = 17 × 3

26.5 + 10n = 51

10n = 51 - 26.5

10n = 24.5

n = 24.5

10

n = 2.45

substitute value of n in (1)

3e + 4 × 2.45 = 13,25

3e + 9.8 = 13.25

3e = 13.25 - 9.8

3e = 3 45

e = 3.45

3

e = 1.15

Cost of an envelope = $1.15

Answer - A $1.15