Question

1) calculati:
a) (4+2³:4)*(-5)²*1,25=...
b) (-2)³ *0,8+(-1) la puterea 2013=....
c) √38(8/√3+7/√27)=...
d) √243 (√2+√32-3√72)=..

Answer 1

a) (4+2³:4)·(-5)²·1,25=(4+2³:2²)·(-5)²·125/100=(4+2^3-2)·25·125/100 simplif.=(4+2)·125/4=6·125/4 simplif=187,5
b) (-2)³ *0,8+(-1)^2013=-8·0,8-1=-6,4-1=-7,4.
c) √38(8/√3+7/√27)=√38(8/√3+7/3√3)=√38(24/3√3+7/3√3)=√38·31/3√3=
31√38/3√3=rationalizam=31√38·3√3/9·3=93√104/9=93·2√26/9=186√26/9=62√26/3
d) √243 (√2+√32-3√72)=9√3(√2+4√2-6√2)=9√3(5√2-6√2)=9√3·(-√2)=-9√6