Answer:
The error she made was that she was adding x and 2.75. She should subtract 2.75 from x.
Another mistake that she made was that she sold each for $7 assuming that she would make a profit of 78, but she should see each necklace for $12.5 so that she could make a profit of $78.
Step-by-step explanation:
The error she made was that she was adding x and 2.75.
She should write the equation as 8 (x - 2.75) = 78; as she spends $2.75 to make a necklace.
By using the correct equation: 8 (x - 2.75) = 78
=> 8x - 22 = 78
=> 8x = 78 + 22
=> 8x = 100
=> x = 100/8
=> x = 12.5
Another mistake that she made was that she sold each for $7 assuming that she would make a profit of 78, but she should see each necklace for $12.5 so that she could make a profit of $78.
Hope this helps you.
Answer:
45/100 = 0.45
Step-by-step explanation:
Divide 9 by 20.
9/20 = 0.45
Now write 36/100 as a decimal.
36/100 = 0.36
Write 45/100 as a decimal: 0.45
Answer: 45/100 = 0.45
Answer:
Randall: 44, Amy: 35
Step-by-step explanation:
Four years ago, their age added up to 71. Since four years have passed and they've each grown four years older since then, their ages added up together is 79. Here is the equation for Amy: x + (x + 9) = 79. We can simplify to get 35. Now we add 9 to 35 to get Randall's age. So, Amy's age is 35 and Randall's age is 44, and 35 + 44 = 79.
Answer:
a) 1+2+3+4+...+396+397+398+399=79800
b) 1+2+3+4+...+546+547+548+549=150975
c) 2+4+6+8+...+72+74+76+78=1560
Step-by-step explanation:
We know that a summation formula for the first n natural numbers:
1+2+3+...+(n-2)+(n-1)+n=\frac{n(n+1)}{2}
We use the formula, we get
a) 1+2+3+4+...+396+397+398+399=\frac{399·(399+1)}{2}=\frac{399· 400}{2}=399· 200=79800
b) 1+2+3+4+...+546+547+548+549=\frac{549·(549+1)}{2}=\frac{549· 550}{2}=549· 275=150975
c)2+4+6+8+...+72+74+76+78=S / ( :2)
1+2+3+4+...+36+37+38+39=S/2
\frac{39·(39+1)}{2}=S/2
\frac{39·40}{2}=S/2
39·40=S
1560=S
Therefore, we get
2+4+6+8+...+72+74+76+78=1560
Answer:
original slope is 1
parallel slope is 1
Step-by-step explanation:
the slopes of parallel lines are equal
original line rise1/run1, slope is 1
parallel line rise2/run2, slope 2/2=1
