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5 votes
As soon as possibel plzz
Thank you

As soon as possibel plzz Thank you-example-1

2 Answers

6 votes

Answer:

The answer is option 1.

Explanation:

First, you have to find the value of y. In order to find y, you have to use the area of rectangle as the question has given the area's value and the expressions for length and width :

Let area be 84 cm²,

Let length be (y+5) cm,

Let width be y cm,

Area = length×width

84 = y(y+5)

84 = y² + 5y

Next, you have to solve this equation by factorization :

y² + 5y = 84

y² + 5y - 84 = 0

y² + 12y - 7y - 84 = 0

y(y+12) - 7(y+12) = 0

(y-7)(y+12) = 0

y - 7 = 0

y = 7 cm

y + 12 = 0

y = -12 cm (rejected)

Lastly, you have to find the perimeter of rectangle using the formula, P = 2l + 2w where l represents length and w is width.

P = 2(y+5) + 2(y)

Let y = 7 cm,

P = 2(7+5) + 2(7)

= 2(12) + 14

= 24 + 14

= 38 cm

User Quad
by
4.2k points
2 votes

Answer:

38

Explanation:

y(y+5)=84

y^2+5y-84=0

Δ=5^2-4*1*(-84)=25+336=361

VΔ=19

y1=(-5+19)/2=7

so P=2*7+2*(7+5)=14+2*12=14+24=38 cm

User AndreaG
by
3.9k points