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If f(x)=-x2(power of ) -5x+18, what is f(-5) a.18 b.68 c. -18 d. -68 e. none of these

User Russel
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1 Answer

4 votes

Answer:

As


  • f(-5)=18

Hence, the option 'a' is true.

Explanation:

Given the expression


f\left(x\right)=-x^2-5x+18

Putting x = -5 in the expression


f\left(-5\right)=-\left(-5\right)^2-5\left(-5\right)+18


=-\left(-5\right)^2+5\cdot \:5+18


=-5^2+5\cdot \:5+18


=-5^2+25+18


=43-5^2


=43-25


=18

Therefore,


  • f(-5)=18

Hence, the option 'a' is true.

User Fremorie
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6.9k points