Question

8o + 12p = 382
12o + 8p = 388

What does p equal?

Answer 1

A simpler way...

Multiplying equation no. 1 with 3 and equation no.2 with 2, we substract them.

`240o + 36p = 1146 \\ - 240o - 16p = - 776`

`20p = 370 \\ p = (370)/(20 ) \\ p = 18.5`

Answer 2

For this case we have a system of two equations with two variables:

Clear "o" from the first equation:

`8o = 382-12p\\o = \frac {382-12p} {8} = \frac {191-6p} {4}`

We substitute in the second equation:

`12 (\frac {191-6p} {4}) + 8p = 388\\3 (191-6p) + 8p = 388\\573-18p + 8p = 388\\-10p = 388-573\\-10p = -185\\p = \frac {185} {10}\\p = 18.5`

ANswer:

`p = 18.5`