Answer:
B) -15
Step-by-step explanation:
To factor quadratic equations of the form ax^2+bx+c=y, you must find two values, j and k, which satisfy two conditions.
jk=ac and j+k=b
The you replace the single linear term bx with jx and kx. Finally then you factor the first pair of terms and the second pair of terms. In this problem...
2k^2-5k-18=0
2k^2+4k-9k-18=0
2k(k+2)-9(k+2)=0
(2k-9)(k+2)=0
so k=-2 and 9/2
k=(-2, 4.5)
After 2 hrs, the car has traveled 90 miles....that means the car travels 90/2 = 45 miles per hr. After 7 hrs...the car has traveled 7 * 45 = 315 miles
The Muslim mathematicians adopted a numerical system from India. The correct answer is B.
Volume of a cylinder=πr^2h
=πx2.5x2.5x12
=πx75
=235.62 cubic inches