Um quadro com área de 4050 cm2 tem de largura duas vezes a sua altura. quais são as dimensões desse quadro?

Step-by-step

Given: a picture frame is twice as wide as it is high and has an area of 4050 cm^2.   Find its dimensions.

Method 1: solve mentally

A quick mental way to solve the problem is to imagine cutting into two lengthwise.  Each half will be a square of 4050/2=2025 cm^2 = 45cm *45 cm

Therefore the frame is 45cm * 90 cm.

Method 2: Using Algebra if pencil and paper is available

Let H=height of the frame

Then 2H = Length of the frame.

Area of frame = Length * Height = 2H *H =4050 cm^2

Solve for H :

2H^2 = 4050

H^2 = 4050/2 = 2025

H = sqrt(2025) = 45 cm

Length = 2H = 90 cm

the correct answer is 828.07

step-by-step explanation:

the original amount doesn't ''re just looking for the time it takes for 1/2 of the substance to we have

(1/2) =)     take the ln   of both sides

ln (1/2)   = )   and we can write

ln(1/2) = ) lne     and lne   = 1     so we have

ln(1/2) = -.1092t     divide both sides by -.1092

t = ln(1/2)/-.1092 = about 6.347 days = about 6.3 days (rounded)