Create equations:
10X+15y=2575.
X+Y=210.
Solve for X: X=210-Y, and sub it into the other equation: 10(210-Y)+15Y=2575. Solve for Y: 2,100-10y+15y=2575, 5y=475, y=95.
Sub Y into the original problem: X+95=210. Solve: X=115.
The first mechanic charges $115 per hour and the second charges $95 :)
16
Place in ascending order: 4 6 8 15 15 17 17 18 20 20
middle numbers = 15 and 17
(15+17)/2 = 16
Pam and her brother both open savings accounts. each begin with a
balance of $0. For every $2 is that Pam saves in her account her brother
saves $5 in his account
P:bro=2:5
when P=40 what is bro?
2/5=40/b
times 5b both sides
2b=200
divide 2
b=100
bro has $100
not sure what tape diagram is
Given the position function, the velocity function is obtained by taking the derivative:
The velocity is increasing its own derivative is positive, so we also have to find the acceleration by taking another derivative:
To find when 
, we first need to know where 
:
The quadratic factor is always positive (its discriminant is negative), which leaves one solution at 
. To either side of , we have, for instance,
which indicates that 
is increasing for 
, making the answer A.
