Hi there! Hopefully this helps!
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<h2 /><h2>Answer: 235.</h2><h2>~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~</h2><h2 />
First we need to <em>substitute the value of the variable</em> into the expression:
10a - 5b = 10(25) - 5(3).
Now we Multiply 10 and 25 to get <u>250</u>.
250 − 5 × 3 = 235
Multiply 5 and 3 to get <u>15</u>.
<u>250</u> − <u>15</u> = 235
<h2>Subtract 15 from 250 to get, you guessed it, 235!</h2>