Question

How do you solve (a-3b)(7a-3b)

Answer 1

Step-by-step explanation:

Simplifying

(7a + 3b)(7a + -3b) = 0

Multiply (7a + 3b) * (7a + -3b)

(7a * (7a + -3b) + 3b * (7a + -3b)) = 0

((7a * 7a + -3b * 7a) + 3b * (7a + -3b)) = 0

Reorder the terms:

((-21ab + 49a2) + 3b * (7a + -3b)) = 0

((-21ab + 49a2) + 3b * (7a + -3b)) = 0

(-21ab + 49a2 + (7a * 3b + -3b * 3b)) = 0

(-21ab + 49a2 + (21ab + -9b2)) = 0

Reorder the terms:

(-21ab + 21ab + 49a2 + -9b2) = 0

Combine like terms: -21ab + 21ab = 0

(0 + 49a2 + -9b2) = 0

(49a2 + -9b2) = 0

Solving

49a2 + -9b2 = 0

Solving for variable 'a'.

Move all terms containing a to the left, all other terms to the right.

Add '9b2' to each side of the equation.

49a2 + -9b2 + 9b2 = 0 + 9b2

Combine like terms: -9b2 + 9b2 = 0

49a2 + 0 = 0 + 9b2

49a2 = 0 + 9b2

Remove the zero:

49a2 = 9b2

Divide each side by '49'.

a2 = 0.1836734694b2  

Simplifying

a2 = 0.1836734694b2

take the square root of each side:

a = {-0.428571429b, 0.428571429b}