Answer:
a) 6x² - 8x
b) 2x² + x - 15
c) 4x² - 25
d) 2x³ + 7x² - 3x
Explanation:
a) 2x (3x - 4)
brackets means multiplication or into
base on the question
2x * 3x = 6x^2
and
2x * (-4) = -8x
therefore
6x² - 8x
is the answer
b) (x + 3) (2x - 5)
clear brackets with (x + 3)
i. x * (2x - 5) = 2x^2 - 5x
ii. +3 * (2x - 5) = 6x - 15
add i add ii
2x² - 5x + 6x - 15
if u noticed, there are similar figures 6x and 5x, so we take like term
2x² + x - 15 answer
c) (2x + 5) (2x - 5)
clear bracket
i. 2x * (2x - 5) = 4x² - 10x
ii. 5 * (2x - 5) = 10x - 25
add i and ii
4x² - 10x + 10x - 25
collect terms
4x² - 25 answer
d) x (2x + 1) (x - 3)
I) first we deal with x(2x+1)
x * (2x + 1) = (2x² + x)
II) then we find the multiplication of
(2x² + x) (x - 3)
i. 2x² * (x - 3) = 2x³ - 6x²
ii. x * (x - 3) = x² - 3x
add i and ii
2x³ - 6x² + x² - 3x
collect terms
2x³ - 5x² - 3x