60 minutes is 20% of 300 minutes
X+y+z=t
simple..
there are no other numbers that we have to follow like (1/2x or 3/4y) so it is just all together=t. the x, y, z will equal t because t is the total number of students taking three languages. And that number should be equivalent to x,y,z combined.
otherwise?? i d k<span />
Eliminate x's
multiply 2nd equation by -2 ad add to first
2x+3y=9
<u>-2x-10y=-16 +</u>
0x-7y=-7
-7y=-7
divide by -7
y=1
sub back
2x+3y=9
2x+3(1)=9
2x+3=9
minus 3
2x=6
divide 2
x=3
x=3
y=1
(x,y)
(3,1)
D
