If you are finding the sample space see if it is biased or not. and if it population then find the experimental or theoretical.
2x+y=-10
Multiply both side by 3
2x*3+y*3=-10*3
6x+3y=-30
3x-y=0
Multiply both side by 2
3x*2-y*2=0*2
6x-2y=0
Next, use substitute property
6x+3y=-30
-
6x-2y=0
=
y=-30
3x-y=0
Substitute y with -30
3x-30=0
Add 30 to each side
3x-30+30=0+30
3x=30
Divided both side by 3
3x/3=30/3
x=10, so the solution pair is (10,-30). In this case, there is the first way to solve these two equation.
Then, I would use equation 3x+1.5y=-15 in this question by multiply 2x+y=-10 by multiplying both side by 3/2 to eliminate x and to solve variables for y. Hope it help!
Step-by-step explanation:
x - y + 5z = 29
y + 2z = 4
z = 7
since z = 7 we can use this value in second equation
y + 2×7 = 4 and y = -10
now we know the value of y we can solve the first equation
x -(-10) + 5×7 = 29
x + 10 + 35 = 29
x = -11