Hi there! Hopefully this helps!
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Answer: 235.
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First we need to substitute the value of the variable into the expression:
10a - 5b = 10(25) - 5(3).
Now we Multiply 10 and 25 to get 250.
250 − 5 × 3 = 235
Multiply 5 and 3 to get 15.
250 − 15 = 235
Subtract 15 from 250 to get, you guessed it, 235!