"find a and b so that the system below has the solution (1, -1)."
ax+2by=0
2ax-4by=16
show work and explain steps.

Trish receives $450 on the first of each month. josh receives $450 on the last day of each month. both trish and josh will receive payments for next four years. at a discount rate of 9.5 percent, what is the difference in the present value of these two sets of payments?

How many triangles can be drawn with side lengths 4 centimeters, 4.5 centimeters, and 9 centimeters? explain

Jonathan can type 20 documents in 40 minutes ,and susan can type it in 30 minutes and jack can type it in 24 minutes working together ,how much time will it is take them type the same document