Answer:
a = √10
Step-by-step explanation:
a² + b² = c²
a² + 9² = (√91)²
a² + 81 = 91
a² = 10
a = √10
hope this helps :)
To solve the equation using complete square method we proceed:
z^2-19z=66
but
c=(-b/2a)^2
c=(-19/2)^2
c=361/4
thus:
z^2-19z+361/4=66+361/4
factoring the LHS we get:
1/4(2z-19)^2=625/4
(2z-19)^2=625
getting the square root of both sides we get:
2z-19=+/-25
2z=+/-25+19
2z=44 or -6
z=22 or -3
Answer: z=22 or z=-3
So it decreases by 11% which means by the next year it's worth 89% of the original price, write 89% like a decimal. then put it to the power of 4 (4 years) and multiply by the original number
.89 ^ 4 * 12250 = 7685.92
The tenths place, starting from the right, it gets higher going to the left. so the tenths place is only ten times greater than it.
I would say 18 because 790-610= 180 and 180÷10= 18