Question

Solve the following equations by using formula

(1) a² − 2a − 4 = 0

(2) x² − 8x + 1 = 0

(3) m² − 2m − 2 = 0

(4) k² − 6k = 1

(5) 2y² + 6y = 3

(6) 8r² = r + 2

(7) p = 5 − 2p²

(8) 2z² + 7z = 4 = 0

(9) 3b² + 2b = 2

(10) a² = 4a + 6

Answer 1

(1)

Comparing the given equation with,

Using the formula :

Hence, the roots of the quadratic equation are

(2)

Comparing the given equation with ,

Using the formula :

Hence, the roots of the quadratic equation are

(3)

Comparing the given equation with ,

Using the formula :

Hence, the roots of the quadratic equation are

(4)

It can be written as .

Comparing the given equation with ,

Using the formula:

Hence, the roots of the quadratic equation are _.

(5)

It can be written as.

Comparing the given equation with ,

Using the formula:

Hence, the roots of the quadratic equation are

(6)

It can be written as .

Comparing the given equation with,

Using the formula:

Hence, the roots of the quadratic equation are

(7)

It can be written as.

Comparing the given equation with,

Using the formula:

Hence, the roots of the quadratic equation are

(8)

Comparing the given equation with _,

Using the formula,

Hence, the roots of the quadratic equation are

(9)

It can be written as

Comparing the given equation with ,

Using the formula:

Hence, the roots of the quadratic equation are

(10)

It can be written as

Comparing the given equation with,

Using the formula:

Hence, the roots of the quadratic equation are