Question

10t+100/2a=10 and 20t+400/2a=30 solve for t

Answer 1

taking 1/2a=x
10t+100x=10------------------1
20t+400x=30------------------2
dividing by 10
t+10x=1
t=1-10x-------------------------3
2t+40x=3----------------------4
putting the value of t in 4
2(1-10x)+40x=3
2-20x+40x=3
20x=1
x=1/20
putting the value of x in 3
t=1-10*1/20
t=1-1/2
t=1/2
Now x=1/2a
1/2a=1/20
by cross multiply.
a=10.

Answer 2

10t+100/2a=10........×2=20t+100/a=20....(i)
20t+400/2a=30....(ii)

subtracting (ii) from (i)
we get
100/a-400/2a=-10
or,a=10

putting a in eq1
20t+20=10
20t=-10
t=-1/2