Given -4(x - 5) = -30, then what is - 2x + 3 ?

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sciencesolve's profile pic

sciencesolve | Teacher | (Level 3) Educator Emeritus

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You should open the brackets using the distributive such that:

`-4x + 20 = -30`

Notice that you may write `-4x + 20`  using the group of terms -`2x+3`  such that: `-4x + 20 = -2x + 3 - 2x + 3 + 14` .

Hence, `-2x + 3 - 2x + 3 + 14 = -30`

Notice that the group of terms occurs two times such that:

`2(-2x+3) = -30 - 14 =gt 2(-2x+3) = -44`

Dividing by 2 yields:

`-2x + 3 = -22`

Hence, evaluating -2x + 3 yields `-2x + 3 = -22` .

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mrsq | High School Teacher | (Level 1) Adjunct Educator

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You are given that -4(x-5) = -30.  So first, we must solve for x in this equation.

-4(x - 5) = -30

-4*x - (-4)(5) = -30           Distribute -4 to everything in the

parenthesis

-4x + 20  = -30       Simplify

-4x + 20 - 20 = -30 - 20 Use inverse operations to solve for x.                                           The inverse of addition is subtraction

-4x = -50 Simplify

-4x/-4 = -50/-4 The inverse of multiplication is division

x = 50/4 = 25/2 Simplify; remember neg/neg = positive

 

Now substitute the value of x  into the second equation and solve:

-2(25/2) + 3

-50/2 + 3 

-25 + 3

-22

Therefore, the value of the second equation is -22.

 

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justaguide | College Teacher | (Level 2) Distinguished Educator

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We are given that -4(x - 5) = -30.

-4(x - 5) = -30

=> -4x + 20 = -30

=> -4x = -50

=> x = 25/2

The value of -2x + 3 = -2*25/2 + 3 = -25 + 3 = -22

The required value of -2x + 3 = -22

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giorgiana1976 | College Teacher | (Level 3) Valedictorian

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We'll have to determine x to compute - 2x + 3.

For this reason, we'll remove the brackets from the 1st equation:

-4x + 20 = -30

-4x = -30 - 20

-4x = -50

x = -50/-4

x  = 12.5

We'll calculate - 2x + 3 :

- 2x + 3 = -25 + 3 = -22

The value of the expression - 2x + 3 is - 2x + 3 = -22.

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