SOLUTION: Hi, I'm having problems figuring these 2 problems out. I have been understanding similar problems, but don't know what I did wrong. Could you please help me? Thanks!!~Leslie Pro

Algebra ->  Equations -> SOLUTION: Hi, I'm having problems figuring these 2 problems out. I have been understanding similar problems, but don't know what I did wrong. Could you please help me? Thanks!!~Leslie Pro      Log On


   

Question 99292: Hi, I'm having problems figuring these 2 problems out. I have been understanding similar problems, but don't know what I did wrong. Could you please help me? Thanks!!~Leslie
Problem# 39: Solve for C: 1/2(c+8)=1/4c


Problem# 41: Solve for A:
%281%2F5%29a+%2B+8+=+%28-3%2F5%29%28a-15%29
Answer by ankor@dixie-net.com(22740) About Me  (Show Source):
You can put this solution on YOUR website!
Problem# 39:
Solve for C:
%281%2F2%29%28c%2B8%29+=+%281%2F4%29c
:
Get rid of the denominator, multiply equation by 4:
4*%281%2F2%29%28c%2B8%29 = 4*%281%2F4%29c
:
Cancel out the denominators and you have;
2(c+8) = 1c
2c + 16 = c; multiply what's inside the brackets
2c - c = -16; subtract c and 16 from both sides
c = -16
:
Check solution by substitution in original equation:
%281%2F2%29%28-16%2B8%29+=+%281%2F4%29%28-16%29
%281%2F2%29%28-8%29+=+%281%2F4%29%28-16%29
-4 = -4
:
:
Problem# 41: Solve for A:
%281%2F5%29a+%2B+8+=+%28-3%2F5%29%28a-15%29
;
Multiply equation by 5 to get rid of the denominators:
5*%281%2F5%29a + 5(8) = 5*%28-3%2F5%29%28a-15%29
:
1a + 40 = -3(a-15)
a + 40 = -3a + 45
a + 3a = 45 - 40
4a = 5
a = 5/4
:
:
Check solution using 1.25 as 5/4:
%281%2F5%291.25+%2B+8+=+%28-3%2F5%29%281.25-15%29
:
.25 + 8 = %28-3%2F5%29%28-13.75%29
8.25 = 8.25 confirms out solution
: