Area=legnth times width or
a=lw
if w=4/5l
and a=320 then subsitute 320 for a dn 4/5l for w
320=4/5l times l
multiply both sides by 5 to clear fraction
1600=4l times l
ad like terms
1600=4l^2
subtract 1600 from both sides
0=4l^2-1600
try and factor because if you have xy=0 then x and/or y=0 so
difference of 2 perfect squares where
if you have a^2-b^2 then that equals(a-b)(a+b) so
0=(2l)^2-(40)^2=(2l-40)(2l+40)
so 2l-40=0
add 40 to both sides
2l=40
divide by 2
l=20
if
2l+40=0
subtract 40 from both sides
2l=-40
divide 2
l=-20
since meausrements of real objects cannot be negative, wediscard this number
l=20 is thhe true legnth s
subsitute
w=4/5l
w=4/5(20)
w=80/5
w=16
legnth=20
width=16
Answer:
x=-1 y =-1
Step-by-step explanation:
multiply equation 1 with (-2)
+6x-2y=-14
5x+2y=3
now add equation 1 to equation 2
11x=-11
x=-1
now substitute x=1 in 1 or 2
5(1)+2y=3 5+2y=3 2y=3-5 2y= -2 y= -1
Answer:
There is not enough info in this question. May you edit this question to have the answer choices? I will edit this answer when you do.
Step-by-step explanation:
