\(\displaystyle{\left|{z}\right|}=\sqrt{{{a}^{{2}}+{b}^{{2}}}}\)

therefore,the magnitude or modulus of the complex number 5i is:

we can write the complex number as 0+5i

therefore the magnitude or modulus of the complex number is \(\displaystyle\sqrt{{{0}^{{2}}+{5}^{{2}}}}=\sqrt{{{5}^{{2}}}}={5}\)

therefore the magnitude or modulus of complex number 5i is 5

the magnitude or modulus of the complex number 7 is:

we can write the complex number as 7+0i

therefore the magnitude or modulus of the complex number is \(\displaystyle\sqrt{{{7}^{{2}}+{0}^{{2}}}}=\sqrt{{{7}^{{2}}}}={7}\)

therefore the magnitude or modulus of complex number 7 is 7

the magnitude or modulus of the complex number 3+4i is:

therefore the magnitude or modulus of the complex number is \(\displaystyle\sqrt{{{3}^{{2}}+{4}^{{2}}}}=\sqrt{{{9}+{16}}}=\sqrt{{25}}={5}\)

therefore the magnitude or modulus of complex 3+4i is 5.

therefore,the magnitude or modulus of the complex number 5i is:

we can write the complex number as 0+5i

therefore the magnitude or modulus of the complex number is \(\displaystyle\sqrt{{{0}^{{2}}+{5}^{{2}}}}=\sqrt{{{5}^{{2}}}}={5}\)

therefore the magnitude or modulus of complex number 5i is 5

the magnitude or modulus of the complex number 7 is:

we can write the complex number as 7+0i

therefore the magnitude or modulus of the complex number is \(\displaystyle\sqrt{{{7}^{{2}}+{0}^{{2}}}}=\sqrt{{{7}^{{2}}}}={7}\)

therefore the magnitude or modulus of complex number 7 is 7

the magnitude or modulus of the complex number 3+4i is:

therefore the magnitude or modulus of the complex number is \(\displaystyle\sqrt{{{3}^{{2}}+{4}^{{2}}}}=\sqrt{{{9}+{16}}}=\sqrt{{25}}={5}\)

therefore the magnitude or modulus of complex 3+4i is 5.