Question

Efectuati:
a)(x-2)(x+2)-x(x+5)
b) m(m-4)+(3-m)(3+m)
c)(4x-a)(4x+a)+2x(x-a)
d)2a(a+b)-(2a+b)(2a-b)
e)(5a-3c)(5a+3c)-(7c-a)(7c+a)
f)(3x-4y)^2-(3x+4y)
g)(2a+6b)(6b-2a)-(2a+6b)^2
h)5a(a-8)-3(a+2)(a-2)
i)(1-4b)(4b+1)+6b(b-2)
j)(8x-y)(y+8x)-(x+y)(x-y)

Answer 1

a)(x-2)(x+2)-x(x+5)=x²-4-x²-5=-9
b) m(m-4)+(3-m)(3+m)=m²-4m+9-m²=9-4m
c)(4x-a)(4x+a)+2x(x-a)=16x²-a²+2x²-2xa=18x²-2xa-a²
d)2a(a+b)-(2a+b)(2a-b)=2a²+2ab-4a²+b²=-2a²+2ab+b²
e)(5a-3c)(5a+3c)-(7c-a)(7c+a)=25a²-9c²-49c²+a²=26a²-58c²
f)(3x-4y)²-(3x+4y)=9x²-24xy+16y²-3x+4y
g)(2a+6b)(6b-2a)-(2a+6b)²=(6b+2a)(6b-2a)-(2a+6b)²=36b²-4a²-4a²-24ab-36b²=
=-8a²-24ab
h)5a(a-8)-3(a+2)(a-2)=5a²-40a-3a²+12=2a²-40a+12
i)(1-4b)(4b+1)+6b(b-2)=(1-4b)(1+4b)+6b(b-2)=1-16b²+6b²-12b=1-10b²-12b
j)(8x-y)(y+8x)-(x+y)(x-y)=(8x-y)(8x+y)-(x+y)(x-y)=64x²-y²-x²+y²=63x²