Question

Va rog e urgent dau coroana ex 24

Answer 1

24.
a)
(2x+1)/5=(y+1)/2
4x+5y=23

4x+2=5y+5
4x-5y=3     ⇒ 4x+5y+4x-5y=23+3   8x=26    x=13/4
y=(23-4×13/4)/5=(23-13)/5=10/5=2



b)
4x-y-24=2(5x-2y)
3y-2=4-(x-y)

4x-y-24=10x-4y
3y-2=4-x+y

6x-3y=-24
x+2y=6

2x-y=-8            y=2x+8
x+2y=6
x+2(2x+8)=6
x+4x+16=6
5x=-10
x=-2
y=-2×2+8=4

c)
2(3x-y)-5=2x-3y
5-(x-2y)=4y+16

6x-2y-5=2x-3y
5-x+2y=4y+16

4x+y=5                y=5-4x
x+2y=-11
x+2(5-4x)=-11
x+10-8x=-11
7x=21
x=3
y=5-4×3=-7