Answer:
1)x=-6,y=1 2)a=0,b=-8 3)j=8,k=1 4)m=3,n=-6
Explanation:
1)x-4y=-10,2x+y=-11
x-4y=-10
x=4y-10
2\left(4y-10\right)+y=-11
8y-20+y=-11
9y-20=-11
9y=9
y=1
x=4-10
x=-6
x=-6,y=1
2)a-3b=24,a+2b=-16
a-3b=24
a=3b+24
3b+24+2b=-16
5b+24=-16
5b=-40
b=-8
a=3\left(-8\right)+24
a=-24+24
a=0
a=0,b=-8
3)k-j=-7
4j-5k=27,-j+k=-7
4j-5k=27
4j=5k+27
j=\frac{1}{4}\left(5k+27\right)
j=\frac{5}{4}k+\frac{27}{4}
-\left(\frac{5}{4}k+\frac{27}{4}\right)+k=-7
-\frac{1}{4}k-\frac{27}{4}=-7
-\frac{1}{4}k=-\frac{1}{4}
k=1
j=\frac{5+27}{4}
j=8
j=8,k=1
4)m+n=-3,m-4n=27
m+n=-3
m=-n-3
-n-3-4n=27
-5n=30
n=-6
m=-\left(-6\right)-3
m=6-3
m=3
m=3,n=-6