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How do you combine #(x^2-bx-7) - (3x^2+2x-4)#?

Answer 1

Hazel Anglin

Group by like powers of #x# and perform standard arithmetic to get:
#color(white)("XXXX")##-2x^2-(b+2)x -3#

#(x^2−bx−7)−(3x^2+2x−4)# #color(white)("XXXX")#Regroup as: #(x^2-3x^2) + (-bx -2x) + (-7 -(-4))#

#=-2x^2 -(b+2)x -3#

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Answer 2

Kennedy Adams

#(x^2-bx-7)-(3x^2+2x-4)=-2x^2-bx-2x-3#

#(x^2-bx-7)-(3x^2+2x-4)#

Distribute the negative sign to each of the terms inside the second set of parentheses, then remove the parentheses.

#x^2-bx-7-3x^2-2x+4#

Group like terms.

#x^2-3x^2-bx-2x-7+4#

Combine.

#-2x^2-bx-2x-3#

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Answer 3

Jameson Allen

To combine (x^2 - bx - 7) - (3x^2 + 2x - 4), you distribute the negative sign to each term inside the parentheses of the second expression and then combine like terms:

(x^2 - bx - 7) - (3x^2 + 2x - 4) = x^2 - bx - 7 - 3x^2 - 2x + 4 = (x^2 - 3x^2) + (-bx - 2x) + (-7 + 4) = -2x^2 - (b + 2)x - 3

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Answer from HIX Tutor

When evaluating a one-sided limit, you need to be careful when a quantity is approaching zero since its sign is different depending on which way it is approaching zero from. Let us look at some examples.