Question 62571
33.
E1: .2x=.3y-2
E2: 1.5y=x+.8
Multiply both E1 and E2 by 10
E1:  10(.2x)=10(.3y-2) ---> 2x=3y-20
E2:  10(1.5y)=10(x+.8) ---> 15y=10x+8
Divide both sides of E1 by 2.
E1: 2x/2=3y/2-20/2 ---> x=(3/2)y-10
Substitute x=(3/2)y-10 in for x in E2 and solve for y.
E2:  {{{15y=10((3/2)y-10)+8}}}
{{{15y=5(3y)-100+8}}}
{{{15y=15y-92}}}
{{{15y-15y=15y-15y-92}}}
{{{0=-92}}} 
The variable was eliminated and 0 does not = -92, therefore there is no solution.   Graphically, these lines are parallel and will never intersect.
: 

35.  
E1:  0.5x+2y=1.15
E2:  -3x+0.4y=-0.7
Multiply E1 by 100 and E2 by 10.
E1:  100(0.5x+2y)=100(1.15) ---> 50x+200y=115
E2:  10(-3x+0.4y)=10(-0.7) ---> -30x+4y=-7
Multiply E2 by -50 and add E1+E2 and the y's are eliminated.
E2: -50(-30x+4y)=-50(-7) --> 1500x-200y=350
:
50x+200y=115
1500x-200y=350
_______________
1550x=465
1550x/1550=465/1550
x=.3
Let x=.3 in the original E1 and solve for y
0.5(.3)+2y=1.15
0.15+2y=1.15
0.15-0.15+2y=1.15-0.15
2y=1
2y/2=1/2
y=.5
The solution is (.3,.5)
Happy Calculating!!!