Answer:
D.f=288.68
Step-by-step explanation:
f+ 523.89 = 812.57
subtract 523.89 from both sides
f+ 523.89-523.89 = 812.57-523.89
f = 288.68
Answer:
no
Step-by-step explanation:
The second purchase is exactly half-again larger than the first purchase, so sheds no light on the relative costs of the items. The per-item costs can be found when the ratio of items purchased is different from one buy to another.
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We can only say that the cost of 1 pear and 3 apples is $7.
Answer:

Step-by-step explanation:
Hello,


It means that

And we know that

So we got two equations

For 
For 
I assume that we are after two different roots so the solution for p is p=-11
b) 
So a quadratic equation with the expected roots is

Hope this helps.
Do not hesitate if you need further explanation.
Thank you
∠ABC is 180°. ∠ABC-∠ABD=68°. Since line BE ∠DBC, 68 divide by 2 is 34°. So ∠EBC is <span>34°.</span>