3. Clearing Fractions and Decimals Under Pressure
GED® Algebra: Skills Hardening & Challenge Practice · preview lesson
When the arithmetic gets heavy, convert it to integers immediately. Multiply every term by the LCD (for fractions) or a power of 10 (for decimals).
Example 1:
\[
\frac{2x-1}{3}-\frac{x+2}{4}=\frac{5}{6}.
\]
LCD of 3, 4, 6 is 12. Multiply every term by 12:
\[
4(2x-1)-3(x+2)=10.
\]
Distribute:
\[
8x-4-3x-6=10.
\]
Combine:
\[
5x-10=10,\qquad 5x=20,\qquad x=4.
\]
Example 2 - decimals:
\[
0.15x-0.4=0.05x+1.1.
\]
Multiply every term by 100:
\[
15x-40=5x+110.
\]
Collect:
\[
10x=150,\qquad x=15.
\]
Common mistake: multiplying only the fraction terms by the LCD and leaving the lone constant untouched.
What is the LCD you should multiply by in \(\frac{2x-1}{3}-\frac{x+2}{4}=\frac{5}{6}\)?
Use the smallest number 3, 4, and 6 all divide into.
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