Answer:
Step-by-step explanation:
# 21.
[tex]\frac{8}{15}[/tex] ÷ ( - 0.35 ) = - [tex]\frac{8}{15}[/tex] ÷ [tex]\frac{35}{100}[/tex] = - [tex]\frac{8}{15}[/tex] ÷ [tex]\frac{7}{20}[/tex] = - [tex]\frac{8}{15}[/tex] × [tex]\frac{20}{7}[/tex] = - [tex]\frac{32}{21}[/tex] (B).
# 22.
( [tex]3\frac{1}{2}[/tex] - [tex]9\frac{3}{4}[/tex] ) ÷ ( - 2.5 )
[tex]3\frac{1}{2}[/tex] = [tex]3\frac{5}{10}[/tex] = 3.5
[tex]9\frac{3}{4}[/tex] = [tex]9\frac{3*25}{4*25}[/tex] = [tex]9\frac{75}{100}[/tex] = 9.75
( 3.5 - 9.75 ) ÷ ( - 2.5 ) = ( - 6.25 ) ÷ ( - 2.5 ) = 2.5 (D).
