Question 479030
1.{{3x-4(5-3x)=5(3x-4)}} show all work

3x-20+12=15x-20      ( when you multiply two negative numbers the result is positive)
3x-8=15x-20
3x-15x=-20+8
-12x=-12
so 
x=1

2.{{{-x +(2/5)=5(-4/3)x}}} solve by clearing fractions show all work

The LCD for the equation is 5*3=15 

Multiply the equation by 15

-15x+(2/5)*15 =5(-4/3)*15x
-15x+6=-100x
85x=-6
x=-6/85



3.{{H=1/4(x-2y)}}  solve for x

Cross multiply
H(4(x-2y))=1
4Hx-8Hy=1
4Hx= 8Hy+1
divide by 4H
x=2y+1/4H

4.{{7x-9 >=-2(x+4)}} solve then write your solution in set notation, show work
7x-9 >=-3x-8
10x>=1
x>=1/10
A={x|x>=1/10}

5.{{P=2w+2l l=78cm.w=12cm. What is the length? show all work}}

P=2*78+2*12
P=156+24
P=180