I did this for you when you were Saphina AlMatary
http://www.jiskha.com/display.cgi?id=1477322557
I gave you a good hint for the second one
Did you even look at it?
Solve the simultaneous questions:
(a) x+y+z=-3 (1)
x-y-2z=13 (2)
y-4z=25 (3)
(b)x+2y+3z=-14 (1)
2x+3y-z=13 (2)
3x-y+2z=-7 (3)
2 answers
In (a),
y=4z+25
so, use that in (1) and (2). Then you just have to solve two equations.
Similarly in (b), #3 gives
y = 3x+2z+7
Use that in (1) and (2)
y=4z+25
so, use that in (1) and (2). Then you just have to solve two equations.
Similarly in (b), #3 gives
y = 3x+2z+7
Use that in (1) and (2)
1 answer