8дм=8м.118дм=1 м18см...720г=7кг20г....незнаю.......2мин=0ч......90мин=1ч30мин
1). а). a+2a^1/2b^1/2+b-2a^1/2b^1/2=a+b; б).(a^1/2-b^1/2)*(a^1/2+b^1/2) / (a^1/2-b^1/2)=a^1/2+b^1/2. 2).2^1,3*2^-0,7*2^1,4=2^(1,3-0,7+1,4)=2^2=4; б). (2^3)^7/3:(3^4)^1,75=2^7:3^7=(2/3)^7=128/2187.
X-761=875-328
x-761=547
x=761+547
x=1308
875-(1308-761)=328