Answer:
18
Step-by-step explanation:
PEMDAS
25-3x(2+1)+9-7
Parentheses first:
2+1=3
Then multiplication
3x3=9
then subtraction
25-9=16
then add
16+9=25
then subtract again
25-7=18
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Parentheses ALWAYS go first. Multiplication/division can be switched and addition/subtraction can be switched, but it always goes parentheses, then multiplication or division and then addition or subtraction.
