Need
3. simplify the expression x^{2} -2x-3/x^{2} -3x-4÷x-3/2x

4. cos (a+b)= cosacosb-sinasinb, then cos (20+60) is what?

Two farmers pay a total rent of $140 for a pasture. the first farmer placed $4 oxen in the pasture, and the second farmer placed $30 sheep in the pasture. the farmers split the rent based on the proportion of the pasture eaten by their own animals that month. how much should the first farmer pay, if 1 ox eats as much as 10 sheep in a month?

Solve the system of equations. y=3x-1 and y=-2x+9. show work

Rose and andrew are financing $128,000 to purchase a condominium. they obtained a 15-year, fixed-rate loan with a rate of 5.05%. they have been given the option of purchasing up to four points to lower their rate to 4.81%. how much will the four points cost them?