Question

Help me substitution method define variables

Answer 1

`\left \{ {{S=14+L} (I) \atop {S+L=124}(II)} \right.`

Substitute (I) into (II), we have:

`S+L=124`

`(14+L)+L=124`

`14 + 2L = 124`

`2L = 124 - 14`

`2L = 110`

`L = (110)/(2)`

`\boxed{L = 55}`

Replace (II) in (I), we have:

`S=14+L`

`S = 14+ 55`

`\boxed{S = 69}`

Answer:
each student sell:
Lori = 55 pizzas
Steve = 69 pizzas