This is correct? I need help please :(

well, we only no that

2l + 2w is 80

(lengths and widths on all 4 sides

and that w * l is A

so the function should be w times what's left for l, but also expressed by something with w

2l + 2w = 80 | -2w

2l = 80 -2w | devide by 2

l = 80 - w

now we can substitute l in

A = w * l

so that we only need w's

A(w) = w * (80-w)

for any w it will give us the area, makes only sense for 0<w<80

the system of inequalities is

step-by-step explanation:

step 1

find the equation of the dashed line

we have the points

(0,0) and (3,1)

the line passes through the origin, so, is a direct variation

find the slope

the equation of the dashed line is

the solution of the inequality a s the shaded area above the dashed line

therefore

the equation of the inequality a is

step 2

find the equation of the solid line

we have the points

(4,0) and (0,4)

find the slope

the equation of the solid line is

the solution of the inequality b s the shaded area below the solid line

therefore

the equation of the inequality b is

step 3

the system of inequalities is

part d

step-by-step explanation:

theresa talked her parents into getting sd cards for her phone and her brother’s phone. inserting an sd card into a phone gives it more storage. they both get 8-gigabyte sd cards. how many bits of storage come with each sd card? type your answer in both scientific and standard notation.