Answer:
16
Step-by-step explanation:
First we have to find 25% of 900 pounds (i hope that's the right currency). so 900 x .25 = 225
so we subtract 225 from 900 and get 675 pounds.
to find sales tax we have to find 6% of 675, so 675 x .06 = 40.50
675 + 40.50 = 715.5 pounds
Let the ladder length be L, then
sin 70 = 20/L, L = 20/sin70 = 21.3 feet
the length of ladder is 21.3 feet
For this case we have the following system of equations:

Equating the values of y we have:

From here, we can clear the value of x.
We have then:

Then, we look for the value of y.
For this, we substitute x in any of the equations:
Answer:
The ordered pair solution of the system of equations, is given by: