Step-by-step explanation:
3x + 5y = 50
x + 5y = 31
use substitution
x = 31-5y
3(31-5y) +5y = 50
93 -15y + 5y = 50
93 - 10y = 50
--10y = -43
y = 43/10 = $4.30 for kids
now solve for x
x + 5(4.30) = 31
x + 21.5 = 31
x = $9.5 for adults
Answer:
7x^2 -128x -19
Step-by-step explanation:
Answer:
Amount of Niobium-91 initially
= 300/91 =3.2967mol
2040 years = 3 ×680 = 3 half-lives
therefore, amount left = 0.4121mol
mass of Niobium-91 remaining = 0.4121 ×91 =37.5g
Please give brainliest
$20 a month. if u subtract the amount that she started with from $85, you get $60. $60 divided by 3 months is $20 a month
3.4+0.4+4.17=7.97 you just have to try different combinations of different numbers with the decimals.
