Answer:
D. 
or 
Step-by-step explanation:
The given equation is:
Divide through by 3;
Add the square of half the coefficient of x to both sides.
The left hand side is now a perfect square:
Take square root
D. or
Answer:
a + b ≥ 40
a + 5 ≤ b
2.50a + 1.50b ≤ 105
Step-by-step explanation:
We are told she would like to have at least 40 cupcakes and cookies combined.
If a is number of cupcakes and b is number of cookies, then this inequality is;
a + b ≥ 40
Secondly, we are told she would like to have at most 5 more cupcakes than cookies.
Thus, the inequality is;
a + 5 ≤ b
Lastly, we are told that cupcakes sell for $2.50 and cookies for $1.50
Thus, the inequality is;
2.50a + 1.50b ≤ 105
Finally, the 3 inequalities are;
a + b ≥ 40
a + 5 ≤ b
2.50a + 1.50b ≤ 105
Negative, because it’s -18 degrees not 18 degrees
