Matematika

12,

a, 2x+3-5x-4+4x-11 = x-12

b, x-10+3(x-2)+4(x+2) = x-10+3x-6+4x+8 = 8x-8

c, 4(2a-b)+5(3a+5b) = 8a-4b+5a+25b = 13a+21b

d, 3x(x-2)-3x(x+5)+5x(x-2) = `3x^2-6x-3x^2-15x+5x^2-10x` = `5x^2-31x`

13,

a, 3a(2a+5) = `6a^2+15a`

b, 5a(3-b) = 15a-5ab

c, 7ab(2a-3b) = `14a^2b-21ab^2`

d, 8ab-16a = 8a(b-2)

e, 21a-28ab = 7a(3-4b)

f, `18ab^2 -24a^2b` = 6ab(3b-4a)

14,

a, (x-1)(x+2) = `x^2-x+2x-2` = `x^2+x-2`

b, (y-2)(y+2) = `y^2-4`

c, (a+1)(3a+2) = `3a^2+3a+2a+2` = `3a^2+5a+2`

d, (2x-y)(2x+y) = `4x^2-y^2`

e, (c+3d)(c+3d) = `c^2+6cd+9d^2`

f, (4a-3b)(4a-3b) = `16a^2-24ab+9b^2`

g, `(a^2+b)(3a^2-4b)` = `3a^4+3a^2b-4a^2b-4b^2` = `3a^4-a^2b-4b^2`