Answer:7.5
Step-by-step explanation: cause I looked it up lol
First you had to remove parenthesis first.

Multiply by the numbers.

Final answer 



Hope this helps!
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-Charlie
A² + b² = c².
Make a triangle with the points on a grid.
One leg is 7 units and the other is 1 unit.
7² is 49 and 1² is 1.
49 + 1 = 50
√50 ≈ 7.071.
Hope this helps!