Va rogggg,urgent,dau coroana

[tex]5)a = {2}^{2} + {2}^{3} + {2}^{4} = 4 + 8 + 16 = 28 \\ {a}^{2} = {28}^{2} = 28 \times 28 = 784 \\ b)784[/tex]
6) D) 60, deoarece 20×3=60
[tex]7)5l = 5 {dm}^{3} \\ b)5 {dm}^{3} [/tex]
8) 47°26'+42°35'=90°1'
B) 90°1'
9) BC=AB÷2=6,4÷2=3,2 cm
B) 3,2 cm