Question

Find k if x²+2(k+1)x+k²=0 has equal roots

Answer 1

For a quadratic equation to have equal roots, it is equal to 0.

∴ b² - 4ac = 0

From the equation,

• a = 1
• b = 2(k + 1)
• c = k²

Substituting the values in discriminant :-

→ 2(k + 1)² - 4(1)(k²) = 0

→ 4k² + 8k + 4 - 4k² = 0

→ 8k + 4 = 0

→ 8k = -4

→ k = -4/8

→ k = -1/2

Answer 2

Step-by-step explanation:

Question:-

the length of a rectangle is 8m more than its breadth if its perimeter is 128m, find its length , breadth and Area

Answer:-

The length of Rectangle is 36 m

The breadth of rectangle is 28 m

The area of Given rectangle is 1008 m².

To find:-

Length and breadth of rectangle

Area of rectangle

Solution:-

Let the breadth be x

Length = 8 + x

Perimeter = 128 m

$\boxed{ \large{ \mathfrak{perimeter = 2(l + b)}}}$

According to question,

$\large{ \tt: \implies \: \: \: \: \: 2(8 + x + x) = 128}$

$\begin{gathered} \large{ \tt: \implies \: \: \: \: \: 8 + 2x = \frac{128}{2} } \\ \end{gathered}:$

$\large{ \tt: \implies \: \: \: \: \: 8 + 2x = 64}$

$\large{ \tt: \implies \: \: \: \: \: 2x = 64 - 8}$

$\large{ \tt: \implies \: \: \: \: \: 2x = 56}$

$\large{ \tt: \implies \: \: \: \: \: x = 28}$

The breadth of rectangle is 28 m

Length = 8 + x = 28 + 8 = 36 m

$\large{ \boxed{ \mathfrak{area = l \times b}}}$

$\large{ \tt: \implies \: \: \: \: \: area = 28\times 36}$

$\large{ \tt: \implies \: \: \: \: \: area = 1008 \: {m}^{2} }$

The area of Given rectangle is 1008 m².