I will give Brainliest its maths and I need help on a b and c

Answer:
[tex] {5}^{3} \times {5}^{x} = {5}^{7} \\ 3 + x = 7 \\ x = 4[/tex]
[tex]( {q}^{2} )^{y} = {q}^{6} \\ 2y = 6 \\ y = 3[/tex]
[tex] {1000}^{m} \div {100}^{n} = {10}^{z} \\ \frac{1000 ^{m} }{ {100}^{n} } = {10}^{z} \\ \\ {10}^{m - n} = {10}^{z} [/tex]
Can I have the brainliest please?