Răspuns:
Explicație pas cu pas:
a) a=1-√2/2+1/2-√2/4+1/4-√2/8 (acum aducem peste tot la numitor cu 8)
a=(8-4√2+4-2√2+2-√2)/8
a=(-7√2+14)/8
a=7(2-√2)/8
b) b=(6/9+7/3) : (1+2√3+3-4)/2
b=(27/9) : (2√3)/2
b=27/9 : √3
b=27/9√3
b=3/√3
b=3√3/3
b=√3
(2+√2)*a=√3*b-5/4
(2+√2)*(14-7√2)/8 = √3 * √3 - 5/4
(28-14√2+14√2-14)/8 = 3 - 5/4
14/8 = 3 - 5/4
14/8 = (12-5)/4
7/4 = 7/4 (A)
