Can someone me with these?

solve each system of equations. check each answer algebraically.
11. -­6x + 3y = 33
-­4x + y = 16
12. 2y = 5x ­-1
x + y = -­1
13. x + y + z = -­1
2x + 4y + z = 1
x + 2y ­- 3z = ­-3

QUESTION 12

The given equations are;

and

Make y the subject in equation (2).

We put this equation (3) into equation (1) to get;

Expand;

Put into equation (3)

QUESTION 12

The given equations are

and

Make y the subject in equation (2)

Put equation (3) into (1)

Put into equation (3).

QUESTION 13

The given equations are

Make x the subject in equation (3).

Put equation (4) into equation (1)

Put equation (4) into equation (2)

Put z=1 in equation (5)

Put y=2 and z=1 into equation(4)

distance covered by pamela in 9 l of fuel = 99km

let us apply unitary method here.

distance covered by pamela in 1 l of fuel =99/9 =11 km

now let us find distance covered by pamela if she has 12 l of fuel.

distance covered in 12 l = distance covered in 1 l of fuel * 12

we know that distance covered by here in 1 l is 11 km.

so distance covered in 12 l of fuel = 11*12 = 132 km.

x/3-10=8

x/3=18

x=48