Question

(х-4)(х+5) (6а-b)(3a-4b)

Answer 1

X^2+5x-4x-20=x^2+x-20
18a^2-24ab-3ab+4b^2=18^2-27ab+4b^2

Answer 2

To expand the given expressions, we can use the distributive property of multiplication. Let's expand each expression:

1. (х-4)(х+5): Use the FOIL method (First, Outer, Inner, Last) to expand the expression. First: х * х = х^2 Outer: х * 5 = 5х Inner: -4 * х = -4х Last: -4 * 5 = -20

   Combining all the terms, we get: х^2 + 5х - 4х - 20

   Simplifying further: х^2 + х - 20

2. (6а-b)(3a-4b): Again, use the FOIL method to expand the expression. First: 6а * 3a = 18а^2 Outer: 6а * -4b = -24ab Inner: -b * 3a = -3ab Last: -b * -4b = 4b^2

   Combining all the terms, we get: 18а^2 - 24ab - 3ab + 4b^2

   Simplifying further: 18а^2 - 27ab + 4b^2

Therefore, the expanded forms of the given expressions are:

1. (х-4)(х+5) = х^2 + х - 20
2. (6а-b)(3a-4b) = 18а^2 - 27ab + 4b^2