The word “increased” indicates the symbol “ ”.
The word “equals” indicates the symbol “”
Let represent number.
Rewrite the sentence into equation,
\The equation is
Apply subtraction property of equality: if , then
.
(Subtract 91 from each side)
(Apply additive inverse property:
)
(Apply additive identity property:
)
(Subtract:
)
Check:
\To check the solution, substitute in original equation.
(Substitute
)
(Add:
)
Compare the values, the equation is true. The solution is .
The value of .