Answer:
15
Step-by-step explanation:
2×6=8
8+7 =15
2+7 =9
9
The answer is: 12.8
71 -7 = 64
64÷5=12.8
X = 12400
20/100 = 1/5
2480 x 5 = 12400
9514 1404 393
Answer:
(a) 1. Distributive property 2. Combine like terms 3. Addition property of equality 4. Division property of equality
Step-by-step explanation:
Replacement of -1/2(8x +2) by -4x -1 is use of the <em>distributive property</em>, eliminating choices B and D.
In step 3, addition of 1 to both sides of the equation is use of the <em>addition property of equality</em>, eliminating choice C. This leaves only choice A.
_____
<em>Additional comment</em>
This problem makes a distinction between the addition property of equality and the subtraction property of equality. They are essentially the same property, since addition of +1 is the same as subtraction of -1. The result shown in Step 3 could be from addition of +1 to both sides of the equation, or it could be from subtraction of -1 from both sides of the equation.
In general, you want to add the opposite of the number you don't want. Here, that number is -1, so we add +1. Of course, adding an opposite is the same as subtracting.
In short, you can argue both choices A and C have correct justifications. The only reason to prefer choice A is that we usually think of adding positive numbers as <em>addition</em>, and adding negative numbers as <em>subtraction</em>.
Answer:
-2
Step-by-step explanation:
→ -9x + 1 = -x + 17
→ -9x + x = 17 - 1
→ -8x = 16
→ x = -16/8
→ [ x = -2 ]
