Question

calcule o valor de b de modo que cada sequencia seja uma pg 45,b,20

Answer 1

$<var>r=\frac{20-45}{3-1}\\r=\frac{-25}{2}\\r=-12,5\\\\a_2=b\\a_2=a_1+r\ logo:\\b=45+(-12,5)\\b=45-12,5\\\\b=32,5</var>$