Question

Calculeaza a) (2^3×12+2^3×13+....+2^3×100)
b) {10^3 +10^2 ×[10+(5^2-5):5]}:30^2​

Answer 1

Răspuns:

Explicație pas cu pas:

2³(12+13+.....+100)=2³×100×101/2-2³(1+2+...+11)=2²×100×101-2³×11×12/2=

=40400-4×11×12=40400-528=39872

b){10³+10²×[10+(25-5)]}:30²=[10³+10²×(10+20)]:30²=(10³+30×10²):3²×10²=

=10²(10+30):3²×10²=40:9