Mircea a citit o cartel in 3 zile .In prima zi a citit un sfert ,a doua zi a citit de doua pro mai mult decat in prima zi,air a treia cat jumatate din prima si inca 25 de pagini . Cate pagini are cartea
I.x/4 II.x/4·2=x/2 III.x/4/2+25=x/8+25 x/4+x/2+x/8+25=x Amplifici prima fractie cu 2, a doua cu 4, 25 si x cu 8 2x/8+4x/8+x/8+200=8x/8 |·8 2x+4x+x+200=8x 7x+200=8x 8x-7x=200 x=200 pagini are cartea
- prima zi x/4 - a doua zi 2x/4=x/2 - a treia zi x/4/2+25=x/8+25
x/4+x/2+x/8+25=x aducem la acelasi numitor.....8 2x/8+4x/8+x/8+200/8=8x/8 eliminam numitorul prin inmultire cu el insusi 2x+4x+x+200=8x 7x+200=8x 8x-7x=200 x=200 pagini are cartea
