The length of a rectangle is 2 1/2 times its width. the permiter of the rectangle is 84cm. find the dimensions of the rectangle

Step-by-step explanation:

The perimeter is twice the sum of the lengths of adjacent sides. If we let w represent the width, then 2.5w can represent the length. The perimeter (in centimeters) is ...

  P = 2(L +W)

  84 = 2(2.5w +w) . . . . . substitute known values

  84 = 7w . . . . . . . . . . . . simplify

  12 = w . . . . . . . . . . . . . .divide by 7

  L = 2.5w = 2.5×12 = 30

The width is 12 cm; the length is 30 cm.

Good evening,

Step-by-step explanation:

f(x) = −16x2 + 60x + 16

Part A: x-intercepts

−16x2 + 60x + 16 = 0

⇔ -4(4x²-15x-4) = 0

⇔ -4[(4x²-16x) + (x-4)] = 0

⇔ -4[4x(x-4) + (x-4)] = 0

⇔ -4(x-4)(4x+1) = 0

⇔ x = 4 or x = -1/4

part B:

since the coefficient of -16x² is -16 which is negative number then the function has a maximum at the point ( -60/2(-16)  ,  f(-60/2(-16)) ) = (15/8 , 289/4).

partC:

first we plot the maximum point then plot x-intercepts 2 points

then we draw the graph.

look at the photo below for the graph.

:)