L = liz's age now
J = Jack's age now
L-1 and J-1 are their ages one year ago
L-1=3(J-1)
L-1=3J-3
L=3J-3+1
L=3J-2 (to be used later)
L+2 and J+2 are their ages in two years
L+2=2(J+2)
replace L by 3J-2
3J-2+2=2(J+2)
3J=2J+4
3J-2J=4
J=4 is Jack's age now
L-1=3(J-1)
L-1=3(4-1)
L-1=3*3
L-1=9
L=9+1
L=10 is Liz's age now
This problem is mainly concerned with setting up an equation.
let's add the interest rates times their respective investment amounts:



simplify:

sum of interest:

1780 = (9000+x) 0.10 + x 0.06 + (11000-2x)0.08


solution:
He does not have any invested in the 6%, while he has 9000 invested at 10% and 11,000 invested at 8%
to check:


So this ended up being a trick problem because he does not actually have any invested in the 6% option.
Hello :
an equation :
(x-1)(x+4)(x+2-i)(x+2+i)
First week : -1.9 + 3.5 = 1.6
2nd week : -2.4
original water level had an increase of 1.6 inches
new water level has a decrease of -2.4 inches
Answer:
4.5 hours
Step-by-step explanation:
Every hour they grow 12 miles part.
54/12=4.5