A) -3√288=-3√(144*2)=-3√144<span>√2=-3*12</span><span>√2=-36</span><span>√2
b) </span>5√320=5<span>√(64*5)=</span>5<span>√64</span><span>√5=5*8</span><span>√5=40</span><span>√5</span>
1/4 hour because since it took him 3/4 hr to milk 3 groups, it is reasonable to divide 3/4 by 3. So in 1/4 hour.
Let x and y be the rate per hour for Mechanic 1 and 2 respectively.
Then,
x+y=205 ---------- (1)
Additionally,
10x+15y = 2500 ------ (2)
Solving equations 1 and 2;
Multiply (1) by 10 and subtract two from the result,
10x+10y = 2050
10x +15 y =2500
----------------------
-5 y = --450 => y = 450/5 = $90
Then,
x= 205-90 = $115
Therefore,
Mechanic 1 charged $115 per hour
Mechanic 2 charged $90 per hour