Harry has a rectangular deck that was 10 ft by 12 ft. He wants to increase the length and width by the same amount and add 75 square feet to the total area.

The additional length is 3 ft

The new length of the rectangle after the increase is 15 ft and the width 13 ft

Step-by-step explanation:

The area A of a rectangle is given as

A = L * B

where L is the length of the rectangle and B is the width

As such for a rectangle 10 ft by 12 ft, the area

= 10 * 12

= 120 sq ft

If this is increased by 75 sq ft, the new area becomes

= 120 + 75

= 195 sq ft

If the length and the width are to be increased by the same amount, let this amount be x then the new length will be 12 + x and width 10 + x such that

(12 + x)(10 + x ) = 195

expand

x² + 22x + 120 =  195

x² + 22x +120 - 195 = 0

x² + 22x - 75 = 0

x² +25x -3x - 75 = 0

x(x +25) -3(x + 25) = 0

(x + 25) (x- 3) = 0

x = -25 or 3

since the additional length cannot be negative, it is 3ft.

As such the new length

= 3 + 12 = 15 ft

the new width

= 10 + 3

= 13 ft

step-by-step explanation:

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)