Answers:
bio = 258
sociology = 169
============================================================
Work Shown:
x = number of bio textbooks
y = number of sociology textbooks
x+y = 427 books sold total
y = x-89 since 89 less sociology textbooks were sold compared to bio
Apply substitution to get the following
x+y = 427
x+x-89 = 427 ... replace y with x-89
2x-89 = 427
2x = 427+89
2x = 516
x = 516/2
x = 258 bio textbooks were sold
y = x-89
y = 258-89
y = 169 sociology textbooks were sold
2x^2 + 28x + 98 =
2(x^2 + 14x + 49) =
2(x + 7)(x + 7) <==
It's the inverse operation of squaring that number. It's an odd definition to explain lol
(NH4)2SO4+SrCl2--><span>(NH4)2Cl2 + SrSO4
The reaction side are both aquas and the product is aquas and a solid precipitate. </span>
