3x = 18 - 3 times girls = # boys = 18
x = 6 - # of girls in the class
Answer:
x² + 7x + 10 = 0
Subtract 10 from both sides
x² + 7x = -10
Use half the x coefficent (7/2) as the complete the square term
(x + 7/2)² = -10 + (7/2)²
note: the number added to "complete the square" is (7/2)² = 49/4
(x + 7/2)² = -10 + 49/4
(x + 7/2)² = 9/4
Take the square root of both sides
x + 7/2 = ±3/2
Subtract 7/2 from both sides
x = -7/2 ± 3/2
x = {-5, -2}
Answer:
87.92
Step-by-step explanation:
c= Circumference
d= Diameter
