Hello.
Parenthesis is going to be your best friend on this problem.
Let's write it out.
-10x² + 6x +5
- (-8x² +10x+5)
_________________ This becomes:
-10x² + 6x +5
+8x² - 10x - 5
________________ Now simplify. Parenthesis disappear because the negative/ subtraction sign has been distributed.
-2x² - 4x
Hope this helped.
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Disclaimer:
Always double check with a reliable source, as mistakes can be made.
