In this section we will deal with equations that have decimal coefficients.
Equations with decimal coefficients are equations of the form:
4.65x - 4.79 = 13.5 - 6.84x
2.33x + 1.456 = 16.9 – 1.22x
Procedure
- Eliminate decimals by multiplying both sides of the equation by a power of 10 that will make the entire coefficients integer.
In the above example: 4.65x - 4.79 = 13.5 - 6.84x
Multiply both sides by 100: (4.65x - 4.79) × 100 = (13.5 - 6.84x) × 100
Now the equation is : 465x - 479 = 1350 – 684x
2. Get the variable terms on one side
Here add 684x both sides: 465x – 479 + 684x = 1350 – 684x + 684x
The equation is: 1149x – 479 = 1350
3. Get the constant terms on one side
Add 479 on both sides: 1149x – 479 + 479= 1350 + 479
The equation is: 1149x = 1829
4. Isolate the variable
Divide both sides by 1149: 1149x ÷ 1149 = 1829 ÷ 1149
Answer: x= 1.59
Further Examples
Consider further examples in solving equations with decimal coefficients:
- Solve : 5.45 + 3t = 7.95 + t
Multiply 100 on both sides
545 + 300t = 795 + 100t
Now we have all integer coefficients
Subtract 545 from both sides
300t = 100t + 795 – 545
300t = 100t + 250
Subtract 100t from both sides
300t – 100t = 250
200t = 250
Divide both sides by 200
Hence t = $$\frac{250}{200}=\frac{5}{4}=1.25$$
2. Solve : 2.3x + 3.9 – 6.62x = 0.12
230x +390 – 662x = 12 ………. Multiply both sides by 100 to clear decimals
-432x + 390 = 12 ……….. Combine like terms
-432x = -378 ……….. Subtract 390 from both sides
X = $$\frac{378}{432}=\frac{7}{8}$$
Summary
The point to remember in solving equations with decimal coefficients is to multiply the entire equation in the beginning by 10, 100, 1000...etc to get rid of the decimals and get proper integer coefficients. After this the equation can be solved in the usual manner by bringing variable on one side and the constant to the other.
Related Tags
Explain Decimal Coefficients , What are Decimal Coefficients , Introduction to Decimal Coefficients
