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37 votes
Hi I need help

1) -15+4r=-9
2)5-y/3=-1
3)42=5x-8
That's all, you don't have to show work, but I'd appreciate it:) asap pls

User Dominic Jonas
by
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2 Answers

22 votes
22 votes

Explanation:

hope it's beneficial.

Draw my attention for further explanations.✨✨

Hi I need help 1) -15+4r=-9 2)5-y/3=-1 3)42=5x-8 That's all, you don't have to show-example-1
User Nedec
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2.5k points
17 votes
17 votes

Equation #1:

  • -15+4r=-9

We move all terms to the left:

-15+4r-(-9)=0

We add all the numbers together, and all the variables

4r-6=0

We move all terms containing r to the left, all other terms to the right

4r=6

r=6/4

r=1+1/2

Equation #2:

  • 5-y/3=-1

We move all terms to the left:

5-y/3-(-1)=0

We add all the numbers together, and all the variables

-y/3+6=0

We multiply all the terms by the denominator

-y+6*3=0

We add all the numbers together, and all the variables

-1y+18=0

We move all terms containing y to the left, all other terms to the right

-y=-18

y=-18/-1

y=+18

Equation #3:

Simplifying

42 = 5x + -8

Reorder the terms:

42 = -8 + 5x

Solving

42 = -8 + 5x

Solving for variable 'x'.

Move all terms containing x to the left, all other terms to the right.

Add '-5x' to each side of the equation.

42 + -5x = -8 + 5x + -5x

Combine like terms: 5x + -5x = 0

42 + -5x = -8 + 0

42 + -5x = -8

Add '-42' to each side of the equation.

42 + -42 + -5x = -8 + -42

Combine like terms: 42 + -42 = 0

0 + -5x = -8 + -42

-5x = -8 + -42

Combine like terms: -8 + -42 = -50

-5x = -50

Divide each side by '-5'.

x = 10

Simplifying

x = 10

User MLu
by
3.1k points