You can start by subtracting different equations from each other.
3x + 2y + 3z = 1
subtract
3x + 2y + z = 7
2z = -6
divide by 2
z = -3
add the following two expressions together:
3x + 2y + z = 7
3x + 2y + 3z =1
6x + 4y + 4z = 8
subtract the following two expressions:
6x + 4y + 4z = 8
5x + 5y + 4z = 3
x - y = 5
^multiply the whole equation above by 3
3x - 3y = 15
subtract the following two expressions:
3x - 3y = 15
3x + 2y = 10
-5y = 5
divide each side by -5
y=-1
take the following expression from earlier:
x - y = 5
substitute y value into above equation
x - - 1 = 5
2 negatives make a positive
x + 1 = 5
subtract 1 from each side
x = 4
Therefore x = 4, y = -1, z = -3
I checked these with all 3 equations and they worked :)
(it's quite complicated, comment if you don't understand anything) :)
ANSWER

EXPLANATION
The given binomial expansion is:

Compare this to

we have a=2x , b=-3y and n=10
We want to find the coefficient of the term

This implies that, r=5.
The terms in the expansion can be obtained using

We substitute the given values to obtain;



Hence the coefficient is;

17.24
Since 7 comes after 5 we need to round to the next number.....18.00
17.24 rounded to ones = 18.00
Hope I helped:P
3\4
because the spaces are bigger draw a model and you will see