equations, need help

[clipperchick14]

I need help with a couple of equations.
Here they are

14. -2(2-5m)=5(2m-2)+6

17. 8r+(6r-4)=9r+6r+5

19. 2(2y+3)-1=-3-4(1-y)

I need all of the steps to these too if possible, I cannot figure them out to save me.

THank you

 

[dagr8est]

Have you learned the distributive property of multiplication?

a(b+c) = ab+ac

 

[clipperchick14]

Yea, but then I get the same #next to a variable. LIke on 19: after like 2 steps I get to 4y+5=-8+4y
What is my next step? I got stuck at the same place for #14

on #17, it says 8r+(7r+-4) i dont know what to do.

 

[dagr8est]

Ahh I see the difficulty these questions are presenting now. There is no value for a that satisfies a = a+b when b≠0. I would just write no solution.

 

[Daniel_Feldman]

14. -2(2-5m)=5(2m-2)+6

-4+10m=10m-10+6

The answer here is the empty set. On paper, it is denoted as a 0 with a diagonal line through it. It means that there are no values for m which satisfy the equation.

17. 8r+(6r-4)=9r+6r+5

14r-4=15r+5

r=-9

19. 2(2y+3)-1=-3-4(1-y)

4y+6-1=-3-4+4y

Same answer as number 14.

 

[clipperchick14]

ok what about: #17
8r+(7r+-4)=15r+5

how do I do the 8r+(7r+-4)?

 

[Denis]

ok what about: #17
8r+(7r+-4)=15r+5
how do I do the 8r+(7r+-4)?

Why are you complicating it?

Your equation:
8r+(6r-4)=9r+6r+5
remove the brackets:
8r + 6r - 4 = 9r + 6r + 5
14r - 4 = 15r + 5
15r - 14r = -4 - 5
r = -9