Answer:
818.87
explanation:
[tex]\hookrightarrow \sf \sqrt{1989\cdot 1989+1989\cdot 1989}+13-2007[/tex]
[tex]\hookrightarrow \sf \sqrt{1989\cdot \:1989+1989\cdot \:1989}-1994[/tex]
[tex]\hookrightarrow \sf 1989\sqrt{2}-1994[/tex]
[tex]\hookrightarrow \sf 818.8707756[/tex]
[tex]\hookrightarrow \sf 818.87[/tex]
[tex] \tt \sqrt{1989 \times 1989 + 1989 \times 1989} + 13 - 2007[/tex]
[tex] \tt \sqrt{ {1989}^{2} + {1989}^{2} } + 13 - 2007[/tex]
[tex] \tt \sqrt{2 \times {1989}^{2} } + 13 - 2007[/tex]
Simplify the radical expression
[tex] \tt1989 \sqrt{2} + 13 - 2007[/tex]
Calculate the difference
[tex] \tt1989 \sqrt{2} - 1994[/tex]
Calculate the approx value
[tex] \tt \approx818.87[/tex]
