Answer:
length=8 , wide=5
Step-by-step explanation:
Let length=x and wide=y
convert the question into two equations
3+y=x .......1
xy=40 .......2
so we need to substitute x into y or y into x
x=3+y ,
(3+y)y=40
y²+3y=40
y²+3y-40=0
from that use calculator or manually factorise it
(y+8)(y-5)=0
y= –8 , y=5
we need to choose positive answer so y=5
then find for x
5x=40
x=8
4.5 4.8 5.1 and 5.4 would be all of them
24000 + 3000x = 30000 + 2400x
3000x - 2400x = 30,000 - 24,000
600x = 6000
x = 6000/600
x = 10 years
Answer: 20
Step-by-step explanation:
x+y=5
x-y=4
---------
x+y=5
x=4+y
--------
(4+y)+y=5
4+y+y=5
4+2y=5
2y=1
y=0.5
x=4.5
---------
x²-y²=(4.5)²-(0.5)²=20.25-0.25=20