Answer :
Combine like terms so add 4b and 15b together and add 7 and 3 together and then the answer would be 19b-10
4b-7-15b+3
=-11b-4
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Explanation:
4b = b+b+b+b
15b = b+b+b+b+b+b+b+b+b+b+b+b+b+b+b
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So...
4b-15b
=(b+b+b+b)-(b+b+b+b+b+b+b+b+b+b+b+b+b+b+b)
=b+b+b+b-b-b-b-b-b-b-b-b-b-b-b-b-b-b-b
=-b-b-b-b-b-b-b-b-b-b-b=-11b
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-7 = -1-1-1-1-1-1-1
3=1+1+1
-7+3=(-1-1-1-1-1-1-1)+(1+1+1)
=-1-1-1-1-1-1-1+1+1+1=-1-1-1-1=-4
=-11b-4
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Explanation:
4b = b+b+b+b
15b = b+b+b+b+b+b+b+b+b+b+b+b+b+b+b
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So...
4b-15b
=(b+b+b+b)-(b+b+b+b+b+b+b+b+b+b+b+b+b+b+b)
=b+b+b+b-b-b-b-b-b-b-b-b-b-b-b-b-b-b-b
=-b-b-b-b-b-b-b-b-b-b-b=-11b
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-7 = -1-1-1-1-1-1-1
3=1+1+1
-7+3=(-1-1-1-1-1-1-1)+(1+1+1)
=-1-1-1-1-1-1-1+1+1+1=-1-1-1-1=-4
