Question

Przekształć iloczyny na sumy:
a) (2a-3= )(4x+7) =
b) (6x-y)(4x+8) =
c) (2x+1)(x+4) =
d) (3m-2)(2m-1) =
e) (2a+3b)(2a-5b) =
f) (2a+3)(5a-4) =
g) (5p-3q)(4p-q) =
h) (3a+2b)(a-b) =
i) (b-3c)(8b+5c) =
j) (5b-4c)(3b-2c) =

Answer 1

a) (2a-3)(4x+7) = 2a*4x + 2a*7 - 3*4x - 3*7 = 8ax + 14a - 12x - 21
b) (6x-y)(4x+8) = 6x*4x + 8*6x - y*4x - 8y = 24x²+48x -4xy - 8y
c) (2x+1)(x+4) = 2x*x + 2x*4+x+4 = 2x² + 9x + 4
d) (3m-2)(2m-1) = 3m*2m - 3m-2*2m+2 = 6m²-7m+2
e) (2a+3b)(2a-5b) =2a*2a-2a*5b+3b*2a-3b*5b = 4a² -10ab+6ab - 15b² =
4a² - 4ab - 15b²
f) (2a+3)(5a-4) = 2a*5a - 4*2a + 3*5a - 12 = 10a² - 8a + 15a-12 = 10a²+7a-12
g) (5p-3q)(4p-q) =5p*4p - 5p*q - 3q*4p + 3q*q = 20p² - 5pg-12pg+3q² =
20p² - 17pg + 3q²
h) (3a+2b)(a-b) = 3a*a - 3ab + 2ab - 2b*b = 3a² - ab - 2b²
i) (b-3c)(8b+5c) = b*8b + b*5c - 3c*8b - 3c*5c = 8b² +5bc-24bc-15c² =
8b²-19bc-15c²
j) (5b-4c)(3b-2c) =5b*3b - 5b*2c - 4c*3b + 4c*2c = 15b² - 10bc - 12bc + 8c² =
15b² - 22bc + 8c²