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4 votes
4 votes
Hi pls help
1) -15+4r=-9
2) 5-y/3=-1
3) 42=-5x-8

User Jpalecek
by
2.7k points

1 Answer

18 votes
18 votes

1) -15+4r=-9

-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

2) 5-y/3=-1

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

3) 42=-5x-8

42=-5x-8

We move all terms to the left:

42-(-5x-8)=0

We get rid of parentheses

5x+8+42=0

We add all the numbers together, and all the variables

5x+50=0

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

5x=-50

x=-50/5

x=-10

User Thomas Brd
by
3.5k points