Answer:
x = - 9, x = 10
Step-by-step explanation:
Given
x² - x - 90 = 0
Consider the factors of the constant term (- 90) which sum to give the coefficient of the x- term (- 1)
The factors are - 10 and + 9, since
- 10 × 9 = - 90 and - 10 + 9 = - 1 , thus
(x - 10)(x + 9) = 0 ← in factored form
Equate each factor to zero and solve for x
x - 10 = 0 ⇒ x = 10
x + 9 = 0 ⇒ x = - 9
lesser x = - 9
greater x = 10
Answer: 140
Step-by-step explanation: 2.5 x 4 = 10
10 x 14 = 140
you multiply the amount of hours she swims for 4 days and then multiply those hours by 14 because the swimming season is 14 weeks long.
Answer:
360
Step-by-step explanation:
multiply 90 and 4
Answer:
Step-by-step explanation:
a ) The worth of Jean-Claude's gnome after 1 year
= 80000 x 1.02
= £81600
b ) common ratio of geometric progression
= 81600 / 80000
= 1.02
c ) worth after 10 years
= 80000 x 1.02¹⁰
= 80000 x 1.21899
= £97519.55
d )
120000 = 80000 x
1.5 = 
ln1.5 = k ln 1.02
k = ln 1.5 / ln 1.02
= .4054 / .0198
= 20.47 years .