Kate has stamped 155 invitations so far.
Step-by-step explanation:
Given,
Total number of invitations = 234
Envelopes left to stamp = 79
Let,
x be the number of envelopes stamped.
According to given statement;
Stamped envelopes + Envelopes left to stamp = Total invitations
[tex]x+79=234[/tex]
Subtracting 79 from both sides
[tex]x+79-79=234-79\\x=155[/tex]
Kate has stamped 155 invitations so far.
Keywords: linear expression, subtraction
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