Question

descompuneti in factori,folosind formula a²-b²= (a-b)(a+b) :
a) x² - 4;
b) 25 - x²;
c) 4x² - 1;
d) 1- 9x²;
e) 16x² - 25;
f) 9 - 4x²

Answer 1

a) (x-2)(x+2)
b)(5-2)(5+2)
c)(2x-1)(2x+1)
d)(1-3x)(1+3x)
e)(4x-5)(4x+5)
f)(3-2x)(3+2x)

Answer 2

x^2-4=(x-2)(x+2); 25-x^2=(5-x)(5+x); 4x^2-1=(2x-1)(2x+1); 1-9x^2=(1-3x)(1+3x); 16x^2-25=(4x-5)(4x+5); 9-4x^2=(3-2x)(3+2x)