Answer:
answer is 7x add the this number
8x - 7 = 3x + 9
8x - 3x = 9 + 7
5x = 16
x = 16/5 = 3 1/5
Answer:
x = -7/4
General Formulas and Concepts:
<u>Pre-Algebra</u>
Order of Operations: BPEMDAS
- Brackets
- Parenthesis
- Exponents
- Multiplication
- Division
- Addition
- Subtraction
Equality Properties
- Multiplication Property of Equality
- Division Property of Equality
- Addition Property of Equality
- Subtract Property of Equality
<u>Algebra I</u>
Step-by-step explanation:
<u>Step 1: Define</u>
5x + 3 - 2x = 12 + 7x - 2
<u>Step 2: Solve for </u><em><u>x</u></em>
- Combine like terms: 3x + 3 = 7x + 10
- [SPE] Subtract 3x on both sides: 3 = 4x + 10
- [SPE] Subtract 10 on both sides: -7 = 4x
- [DPE] Divide 4 on both sides: -7/4 = x
- Rewrite: x = -7/4
<u>Step 3: Check</u>
<em>Plug in x into the original equation to verify it's a solution.</em>
- Substitute in <em>x</em>: 5(-7/4) + 3 - 2(-7/4) = 12 + 7(-7/4) - 2
- Multiply: -35/4 + 3 + 7/2 = 12 - 49/4 - 2
- Add: -23/4 + 7/2 = 12 - 49/4 - 2
- Add: -9/4 = 12 - 49/4 - 2
- Subtract: -9/4 = -1/4 - 2
- Subtract: -9/4 = -9/4
Here we see that -9/4 does indeed equal -9/4.
∴ x = -7/4 is the solution to the equation.
Associative property is only applied to addition and multiplication. Thus, it can't be applied to subtraction. This property is manifested when you get the same answer no matter where you put the parenthesis. Example of associative property is:
(50 + 2) + (92 + 6) = 52+98 = 150
50 + (2+92) + 6 = 50 + 94 + 6 = 150
Here is the counter example for the subtraction of decimals:
(3.45 - 8.92) - (1.9 - 7.3) = -5.47 - ⁻5.4 = -0.07
3.45 - (8.92 - 1.9) - 7.3 = 3.45 - 7.02 - 1.9 = -5.47
As you can see, the answers are not the same.
