
- Equations and Applications
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- Additive property of equality with decimals
- Multiplicative property of equality with decimals
- Multiplicative property of equality with whole numbers: Fractional answers
- Multiplicative property of equality with fractions
- Using two steps to solve an equation with whole numbers
- Solving an equation with parentheses
- Solving a fraction word problem using a linear equation of the form Ax = B
- Translating a sentence into a multi-step equation
Additive property of equality with decimals
The additive property of equality states that we can add (or subtract) the same number (or algebraic expression) to both sides of an equation without changing the solution.
If a, b and c are any three numbers
if a = b, then
1. a + c = b + c
2. a − c = b − c
Solve for x
x + 2.7 = 8.9
Solution
Step 1:
To solve for x, we must isolate x. On left side of equation, we have x + 2.7; to isolate x, we must subtract 2.7.
Step 2:
From the additive property of equality with decimals we must subtract from both sides of an equation the same number. So, we subtract 2.7 from both sides as follows
x + 2.7 – 2.7 = 8.9 − 2.7
Step 3:
Simplifying
x = 8.9 − 2.7 = 6.2
So, x = 6.2
Solve for x
x − 1.3 = 11.7
Solution
Step 1:
To solve for x, we must isolate x. On left side of equation, we have x − 1.3; to isolate x, we must add 1.3
Step 2:
From the additive property of equality with decimals we must add to both sides of an equation the same number. So, we add 1.3 to both sides as follows
x – 1.3 + 1.3 = 11.7 + 1.3
Step 3:
Simplifying
x = 11.7 + 1.3 = 13.0
So, x = 13