physics ( math)
posted by K.C .
Solve the Equations in terms of X:
a. x/a = b/c
b. s=xt^2/2
d. 4= 10/x
e. 5= 5/x5
f. 40=2((x10)25)
g. x(y+2)/ (5y +8)
1.What is the average of 2/9 and 4/5?
2. Subtract 4.20 x 10^5 from 6.468 x 10^4
3.Given: D= density; M= Mass; V= Volume; and D= M/V
a) If an object has a density of 1.5g/cm cubed and a volume of 3 cm cubed, how much it weigh?
b) If an object has a density of 1.5g/cm cubed and a mass of 4.5g, what is its volume?
4. A car travels in 125 miles in 2 and a half hours. What is its average speed?
Thanks in advance and will appreciate it work is shown so i can be able to learn and do it myself the next time...

a thoough g are basic algebra questions. If you cannot do any of them, you should not be taking physics. Show us your work so someone can explain where help is needed.
1. The average of two numbers is their sum divided by 2.
2. Write the numbers so that the exponent of 10 is the same. The subtract the mumbers in front.
6.468x104
0.042x10^4

6.426 x 10^4
3a M = V*D
3b V = M/D
4. 125 / 2.5 = __ mph? 
and g is not an equation..