Answer: 410526 books
Step-by-step explanation:
Let x equal the total number sold.
x × 0.076 = 31,200
x = 410526 books
Answer:
4x +7y
Step-by-step explanation:
(8x +10y) +(-4x -3y) = x(8 -4) +y(10 -3) = 4x +7y
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Combine like terms. Pay attention to signs.
Answer:
-d^3 + d^2
Step-by-step explanation:
Answer:
y = x² + 7x + 4
Step-by-step explanation:
<u>First option</u>
System of equations:
y = x² + x – 4
y = x – 5
Replacing:
x - 5 = x² + x – 4
0 = x² + x – 4 - x + 5
0 = x² + 1
Discriminant:
b²-4*a*c
0²-4*1*1
-4 < 0 then the equation has no real roots
<u>Second option</u>
System of equations:
y = x² + 2x – 1
y = x – 5
Replacing:
x - 5 = x² + 2x – 1
0 = x² + 2x - 1 - x + 5
0 = x² + x + 4
Discriminant:
b²-4*a*c
1²-4*1*4
-15 < 0 then the equation has no real roots
<u>Third option</u>
System of equations:
y = x² + 6x + 9
y = x – 5
Replacing:
x - 5 = x² + 6x + 9
0 = x² + 6x + 9 - x + 5
0 = x² + 5x + 4
Discriminant:
b²-4*a*c
5²-4*1*4
9 > 0 then the equation has two different real roots
<u>Fourth option</u>
System of equations:
y = x² + 7x + 4
y = x – 5
Replacing:
x - 5 = x² + 7x + 4
0 = x² + 7x + 4 - x + 5
0 = x² + 6x + 9
Discriminant:
b²-4*a*c
6²-4*1*9
0 then the equation has one real root
