Answer:
96
Step-by-step explanation: 12+3=15 15x8= 120 then take out the 3 from the 15 and do 12x8 and it's 96.
For this case we have a function of the form:

Where,
A: initial value of an autographed baseball
b: growth rate
x: number of years
Substituting values we have:

For the moment when the value is at least 650 $ we have the following inequality:

Answer:
a one-variable inequality that could be used to solve for the number of years, x, it would take for the baseball to be worth at least $650 is:

Answer:
3 gallons of diesel weighs 22.2 pounds.
The constant of variation is 7.4
The quantities vary directly
Step-by-step explanation:
37/5=7.4 (constant of variation)
7.4*3=22.2
The quantities vary directly because if the amount of gallons go down, so do the pounds. And direct is if x lowers, so does y.
Solve the following system using elimination:
{15 y - 14 x = 15 | (equation 1)
{21 x - 20 y = -10 | (equation 2)
Swap equation 1 with equation 2:
{21 x - 20 y = -10 | (equation 1)
{-(14 x) + 15 y = 15 | (equation 2)
Add 2/3 × (equation 1) to equation 2:
{21 x - 20 y = -10 | (equation 1)
{0 x+(5 y)/3 = 25/3 | (equation 2)
Multiply equation 2 by 3/5:
{21 x - 20 y = -10 | (equation 1)
{0 x+y = 5 | (equation 2)
Add 20 × (equation 2) to equation 1:
{21 x+0 y = 90 | (equation 1)
{0 x+y = 5 | (equation 2)
Divide equation 1 by 21:
{x+0 y = 30/7 | (equation 1)
{0 x+y = 5 | (equation 2)
Collect results:
Answer: {x = 30/7, y = 5