Answer:
[tex]\frac{71}{40}\ kg[/tex] or [tex]1\frac{31}{40}\ kg[/tex]
Step-by-step explanation:
Let
x-------> the average weight of the newborn otter
we know that
[tex]x-\frac{9}{10}=\frac{7}{8}[/tex] -----> linear equation that represent the situation
solve for x
Adds [tex]\frac{9}{10}[/tex] both sides
[tex]x=\frac{7}{8}+\frac{9}{10}[/tex]
[tex]x=\frac{10*7+8*9}{80}\\ \\x=\frac{142}{80}[/tex]
Simplify
[tex]x=\frac{71}{40}\ kg[/tex]
Convert to mixed number
[tex]\frac{71}{40}=\frac{40}{40}+\frac{31}{40}=1\frac{31}{40}\ kg[/tex]
