1.) 3/5+2/15=11/5
2.) 5/12(1/12+1/4)=5/12(1/3)=5/36
3.) 1/25+3/20+4/25+1/20=5/25+4/20=1/5+1/5=2/5
4.)3/5+5/6-7/30=18+25-7/30=6/5
9у-17=5-2(4-7у)
9у-17=5-8+14у
9у-14у=5-8+17
-5у=20
у=4
а) (6 - 1 1/2 - 1/3) : (6 +1 1/2 - 1/3) =
1) 6 - 1 1/2 = 5 - 1/2 = 4 2/2 - 1/2 = 4 1/2
2) 4 1/2 - 1/3 = 4 +(3-2)/6 = 4 1/6
3) 6 + 1 1/2 = 7 1/2
4) 7 1/2 - 1/3 = 7 +(3-2)/6 = 7 1/6
5) 4 1/6 : 7 1/6 = 25/6 : 43/6 = 25/6 *6/43 = 25/43
б) 1:1 +1:1 +1:1 + 1/3 = 3 1/3
6^(x+1)+30*6^x=1
6^x*6¹+30*6^x=1
6^x*(6+30)=1
6^x*36=1
6^x=1/36
6^x=(1/6)²
6^x=6⁻²
x=-2