Answer:
See below
Step-by-step explanation:
[tex] {5}^{2} - {1}^{2} \times {2}^{2} \\ \\ = 25 - 1 \times 4 \\ \\ = 25 - 4 \\ \\ = 21 \\ \\ \\ {7}^{2} + {4}^{3} \div {2}^{5} \\ \\ = {7}^{2} +( {2}^{2} )^{3} \div {2}^{5} \\ \\ = {7}^{2} + {2}^{2 \times 3} \div {2}^{5} \\ \\ = {7}^{2} + {2}^{6} \div {2}^{5} \\ \\ = {7}^{2} + {2}^{6 - 5} \\ \\ = 49 + {2}\\ \\ = 51[/tex]
