I think it might be c hope that helps you
13 divided by 11.3 is 1.150442477876106. So 15 by 1.150442477876106 and you get 13.03846162772485. Just round it to the nearest tenth and you get 13.0.
Alot of equations
x+1=26
x=3+22
x^2=625
x/2=12.5
4x=100
etc
we have given that
.
we need to find
.
we know that we need to plug t in place of x in the equation f(x)=2^x.
.for example for 
they have plugged 4 in place of x. so we plug in plug t in place of x .