The simplified expression are as follows;
6mn³ - mn² + 3mn³ + 15mn² = 9mn³ + 14mn²
a⁴b³ + 8a⁴b³ = 9a⁴b³
<h3>How to simplify an expression?</h3>
A simplified expression is express to its lowest term.
Therefore,
6mn³ - mn² + 3mn³ + 15mn²
combine like terms
6mn³ + 3mn³ - mn² + 15mn²
9mn³ + 14mn²
a⁴b³ + 8a⁴b³ = 9a⁴b³
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M equals 3x+21 because you add 2x+1x=3x.then you add 14+7=21.then you combine them together to get 3x+21
Answer:

Step-by-step explanation:
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Answer:
-7x-48
Step-by-step explanation:
2x-3(20-3x)+12
2x-60-9x+12 (distribute)
-7x-48
hope this helps
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