maths(form 2english)

1.p-q=0...(1)
p+4q+1=0...(2)
in(1)..p=q...(3)
sub(3)into(2)
q+4q+1=0
5q=-1
q=-0.2 p=-0.2

2.x+y=3...(1)
5x=3y-1...(2)
in(1) x=3-y..(3)
sub(3)into(2)
5(3-y)=3y-1
15-5y=3y-1
2y=16
y=8...(4)
sub(4)into (1)
X+8=3
x=-5


3.2c+5d=27...(1)
c+2d=9..(2)
in(2) c=9-2d...(3)
sub(3)into(1)
2(9-2d)+5d=27
18-4d+5d=27
d=9...(4)
sub(4)into(2)
c+18=9
c=-9

4.3y-5x=4..(1)
5x-y=2...(2)
in(2) 5x=2+y..(3)
sub(3)into (1)
3y-(2+y)=4
3y-2-y=4
2y=6
y=3...(4)
sub(4)into(2)
5x-3=2
5x=5
x=1

1. p-q=0...1
p+4q+1=0...2

From (1),
p-q =0
p=q.....3

substitute (3) into (2),
p+4p+1=0
5p=-1
p= -1/5

Sincep=q, q=-1/5


2. x+y=3...1
5x=3y-1...2

From (1),
x+y=3
x=3-y.....3

substitute (3) into (2),
5(3-y)=3y-1
15-5y=3y-1
8y=16
y=2

Since x=3-y
x=1


３. 2c+5d=27...1
c+2d=9....2

From (2),
c+2d=9
c=9-2d.....3

substitute (3) into (1),
2c+5d=27
2(9-2d)+5d=27
18-4d+5d =27
d =9

Since c=9-2d
c=-9


4.3y-5x=4....1
5x-y=2.......2

From (2),
5x-y=2
y=5x-2.........3

substitute (3) into (1),
3(5x-2)-5x=4
15x-6-5x=4
10x=10
x=1

Since y=5x-2
y=3

1.p-q=0----(1)
p+4q+1=0-----(2)
(1):
p=q
sub into (2)
q+4q+1=0
5q=1
q=1/5
p=1/5

2.x+y=3----(1)
5x=3y-1----(2)
(1):
x=3-y
sub into (2)
5(3-y)=3y-1
15-5y=3y-1
16=8y
y=2
x=3-y
x=3-2
x=1

3.2c+5d=27-----(1)
c+2d=9------(2)

(2):
c=9-2d
sub into (1)
2(9-2d)+5d=27
18-4d+5d=27
18-d=27
-d=9
d=-9
c=9-2d
c=9-2(-9)
c=9-(-18)
c=27

4.3y-5x=4----(1)
5x-y=2----(2)

(2):
5x-y=2
-y=2-5x
y=5x+2
sub into (1)
3(5x+2)-5x=4
15x+6-5x=4
10x+6=4
10x=-2
x=-2/10
x=-1/5
y=5x+2
y=5(-1/5)+2
y=-1+2
y=1