<span>(x+1)²=(x-2)²
х²+2х+1=х²-4х+4
2х+4х=4-1
6х=3
х=0,5
</span>
1) ( 1 + √ 7 )( 4 - √ 7 ) = 4 - √ 7 + 4√7 - 7 = 3√7 - 3
2) ( 3√ 7 - 3 )* 3√ 7 = 9*7 - 9√ 7 = 63 - 9√7
3) 63 - 9√ 7 + 9√7 = 63
ОТВЕТ 63
1) 10а^4-5а^3+15а^2
2) 3с^2-4сх-8сх+8х^2=3с^2-12сх+8х^2
3) а^2+4аb+4b^2
0,5*1,7*20+3 3/7 * 28 - 3 1/7 *28=10*1,7+28(3 3/7 - 3 1/7)=
17+28* 2/7=17+4*2/1=17+8=25