Răspuns:
Explicație pas cu pas:
7.
√5²(3²+4²)=√5²×5²=5²
30²-18²=(30-18)(30+18)=12×12×4
√6²(3²+4²)=6×5
5²/12×2+30=5(5+6×24)=5×149=745
9.
2 (45-4)/90+4+1/4+5-√6+(1+√6)/(-5)=221/90+9+1/4-√6-(1+√6)/5=
=(221+162)/90+(1-5√6-4-4√6)/20=383/90-(3+9√6)/20
