Question

Please answer any question from 5 to 12 and I promise to mark your answer as the brainliest

Answer 1

Answer:

10) 3x - 8y = 0

7) a = 4

Step-by-step explanation:

10) Take pencils as x

And erasers as y.

Cost of 3 pencils = Cost of 8 erasers.

= 3x = 8y

= 3x - 8y = 0

7) x = 2, y = 1

Substitute these values in the equation you get,

9x - 3ay = 6

= 9 (2) - 3 (1) a = 6

= 18 - 3a = 6

= - 3a = 6 - 18

= - 3a = -12

= a = 4