Answer:
3ac-a+2b
a=2,b=1,c=4
Step-by-step explanation:
3*2*4-2+2*1
24-2+2=24
Answer:
First, you have to form simultaneous equation for both of their ages in yerms of a and b :
b = 4a - 12 -------- ( 1 )
a + b = 28 -------- ( 2 )
Next, you will have to solve it by substituting ( 1 ) into ( 2 ) :
a + (4a - 12) = 28
5a - 12 = 28
5a = 28 + 12
5a = 40
a = 8
Then, substitute a = 8 into ( 1 ) :
b = 4(8) - 12
b = 32 - 12
b = 20
The mechanical advantage of the block and tackle is that it is easier to lift a lock using multiple parts of the rope that go around the system of pulleys. If there are no friction, the mechanical advantage is exactly equal to the number of parts of the rope that are attached to the load.
