To solve this, we need to first distribute the 0.34 to both terms inside the parentheses:

(1 13/20 - 0.3x) 0.34 = 4 1/2
1 13/20 0.34 - 0.3x 0.34 = 4 1/2
0.7 0.34 - 0.3 0.34 x = 4.5

Now, we can simplify the left side:

0.238 - 0.102x = 4.5

Next, we can isolate the variable by moving 0.238 to the other side:

-0.102x = 4.5 - 0.238
-0.102x = 4.262

Finally, solve for x by dividing by -0.102:

x = 4.262 / -0.102
x = -41.86

Therefore, x is approximately -41.86.